How to Grow Chilli Plants
.jpg "Chilli Harvest - 29th October 2024")
Before we begin, I'd just like to mention that I live in the UK, so most of the information on this page is more relevant to UK chilli growers than it is to growers living in other parts of the world. If you live somewhere with a warmer climate and a longer growing season or somewhere with a colder climate and a much shorter growing season then obviously some of the information on this page will vary for you. For example, if you live somewhere with a much warmer climate you'll be able to grow your chilli plants outside in the garden instead of in a polytunnel or a greenhouse, but due to the higher temperatures you'll also need to water your chilli plants more frequently than those of us living in cooler parts of the world. You'll also be able to sow your chilli seeds at a later date than those of us living in temperate zones.
Everyone's plant growing situation is different. Some people may only have space to grow a few plants indoors in a porch, conservatory or a sunny south-facing window. Others may only have the space or the permission to grow their plants outside on a balcony or in a greenhouse or garden. Some people may have several large greenhouses that they can dedicate solely to growing hundreds of chilli plants every year. Some people may live in a sunny part of the world where they are guaranteed to get nice weather throughout the summer months, allowing them to grow gigantic plants outside in the garden in large pots or directly in the ground. Other people may live in a part of the world where the chilli growing season is fairly short and the weather during the summer months is very unpredictable, forcing them to grow their chilli plants in pots in a polytunnel or greenhouse, which can then be moved indoors to allow the fruit to ripen once the temperatures start to drop.
Some people may only use rainwater when watering their chilli plants and other people may only use tap water. Some people may have a devout allegiance to a certain fertiliser brand or compost brand and may be so set in their ways that they're not prepared to try anything else. Some people may harvest one or two bagsful of ripe chillies at the end of the growing season and other people may harvest many large bucketsful. It's not a competition. Whether you plan on growing monster chilli plants outside in your garden in huge pots or whether you plan on growing much smaller plants indoors, the most important thing is that you have fun growing your chilli plants and that you harvest delicious ripe chillies at the end of the growing season. There are many roads leading to Rome, and the map on this page is the route that I take. You and some of the people you know may take a different route, but so long as you arrive at your destination on time then it doesn't really matter.
Growing chilli plants isn't difficult, and if you read the information on this page in its entirety then there's no reason why you too won't be able to grow chilli plants and harvest your own ripe chillies at the end of the season to use in your favourite curries and other spicy concoctions. As long as you provide your chilli plants with warmth, sun/light, water and fertiliser, and you check them on a regular basis for pests then the rest is normally easy. In most cases, the trickiest part can be germinating the seeds. When I set this website up in 2018 I never intended to put together a page on growing chilli plants because that information can already be found all over the wide-eyed web. However, many people have asked me over the years where they can find the URL to the page on growing chilli plants, so in early 2024 I decided to put this page together.
The chilli variety that I chose for this page example is Aji Mochero, a lovely Capsicum chinense variety from Peru. However, don't be put off because the information shown on this page works for all chilli varieties belonging to the C. annuum, C. baccatum, C. chinense, C. frutescens and C. pubescens species, which are the five domesticated Capsicum species. It also works for wild Capsicum species too, but some wild species can be a bit trickier to germinate, so for the sake of this page I'll just be focusing on the five domesticated Capsicum species, which are the ones that most people grow and are interested in.
When Should I Sow Chilli Seeds in the UK?
The time to sow chilli seeds in the UK is anywhere between mid-December to the beginning of March. Most UK chilli growers sow their chilli seeds in January and then raise their seedlings under grow lights. However, some growers who are a little more eager may decide to start them in December. Before I started using grow lights I sowed all of my chilli seeds during the first week of March every year and then raised the seedlings in a porch using natural light. However, nowadays, I sow my chilli seeds anywhere between the beginning of January and the middle of February. Sometimes, I may start them in January and raise the seedlings under grow lights and sometimes I may start them in the middle of February and raise the seedlings using natural light. Both methods work fine for me but each one is slightly different.
An advantage to sowing chilli seeds early is that it gives you plenty of time to sow another batch should the first batch of seeds fail to germinate or should the seedlings look unhealthy. I recommend that you don't sow your chilli seeds any later than early March if you live in the UK. Although I have been able to sow Habanero seeds in early May and harvest ripe fruit in early December, not everyone can grow their plants indoors like I can. Most people can only grow them outside in a greenhouse, so if you want to harvest ripe chillies in October or early November then you shouldn't sow your chilli seeds any later than early March, but sowing them in February is a much better choice.
If you're able to provide your seedlings with adequate warmth and natural light in February then you can sow your chilli seeds in February without needing to use grow lights, but for best results you'll need to use grow lights when starting them early. Just remember that the chilli growing season for greenhouse growers in the UK normally comes to an end around late October to mid-November once the night time temperatures start to drop. I tend to grow most of my chilli plants indoors, and when growing them indoors it's possible to extend the growing season by a few more weeks. If you intend to raise your seedlings using natural light then a porch or a conservatory is a much better option than a windowsill because they'll get the light from all sides and above as opposed to just from the front.
Some Capsicum species require a longer growing season than others. Capsicum chinense and Capsicum pubescens varieties are slower to mature and require a longer growing season than Capsicum annuum, Capsicum baccatum and Capsicum frutescens varieties, although there are some early C. chinense varieties in existence. Growers who sow their chilli seeds in January typically start their C. chinense and C. pubescens and any wild varieties they may be growing first, followed by their C. annuum, C. baccatum and C. frutescens varieties about four or five weeks later. I sow all of my chilli seeds, regardless of the species, at the same time because I normally start them off later than most other UK chilli growers do.
Do Chilli Seeds Need to Be Soaked Prior to Sowing?
Some chilli growers prefer to soak their chilli seeds for a few hours or overnight prior to sowing them, whereas others prefer not to bother. Personally, I'm of the camp that prefers not to bother. The idea behind soaking seeds is to hydrate them, to soften the seed casing and to speed up the germination process. Occasionally, some seedlings may break through the compost with the seed casing still attached, an issue which is often referred to by some growers as 'helmet heads'. Soaking chilli seeds prior to sowing them is believed to eliminate this problem. However, on the occasions when I have soaked chilli seeds overnight I've still had some seedlings emerge from the compost with the seed casing still attached. In such cases, if you leave them alone the seed casing will normally fall off eventually or the seedling will open its seed leaves (cotyledons) after a few days and the seed casing will remain attached to one of the seed leaves.
The liquids or solutions that people use for soaking chilli seeds can vary. Some people may use a dilute black tea or camomile tea; others may use hydrogen peroxide, saltpetre (potassium nitrate), sugar water or just plain water. The tannins in black tea are said to soften the seed casing, and camomile tea is believed to contain anti-fungal properties which help protect the seeds from soil borne pathogens. Soaking seeds in a 1–3% solution of hydrogen peroxide for a specified amount of time is believed to be good for reviving old seeds. Saltpetre is believed to soften the seed casing and make germination easier and faster. Soaking seeds in sugar water is believed to bolster the carbohydrate levels, which in turn helps to revive sluggish or old seeds. The types of sugar used can be molasses, black strap molasses, malt extract or regular table sugar. Soaking seeds in plain water is just to hydrate them prior to sowing.
Note: When a seed absorbs water the process is known as imbibition, and when seeds are soaked in liquids or solutions that soften the seed casing the process is known as chemical scarification.
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| Chilli Seeds Soaking in Black Tea |
To make a dilute black tea or camomile tea for soaking chilli seeds, place your teabag of choice into 300ml of hot water and squeeze it against the sides of the vessel a few times in the same way you would when making yourself a cup of tea. Leave it steep for 5 minutes and then remove and discard the teabag. Add an additional 300ml of cold water to the hot tea and then wait until it has cooled sufficiently before using it to soak your chilli seeds. To make up a sugar water solution, dissolve 2–3 teaspoons of your sugar of choice into 300ml of hot water and then wait until it has cooled sufficiently before using it. You can safely soak chilli seeds in black tea, camomile tea, sugar water or plain water for up to 24 hours without any problems. The recommended time for soaking chilli seeds in hydrogen peroxide ranges from 5 minutes to 24 hours, depending on whom you ask. Some scientific sources even suggest soaking seeds in hydrogen peroxide for up to 48 hours, but I've never tried this! The recommended time for soaking chilli seeds in saltpetre ranges from 2 to 24 hours.
Whether you choose to soak your chilli seeds or not is entirely your choice. I have soaked chilli seeds in all of the aforementioned liquids and solutions for varying lengths of time and have never noticed any difference with germination times or germination rates, hence why I now just sow them directly into the compost. However, every grower has his or her own preferred way of doing things. Some growers swear by soaking their chilli seeds, almost to the point of it being ritualistic! If you're new to growing chilli plants then you'll eventually develop your own way of doing things that works best for you.
Some growers even swear by sowing their chilli seeds during a full moon because they believe that the gravitational pull on the Earth's water has a positive effect on germination and plant growth. If you choose to soak your chilli seeds just know that most seeds will initially float, but once they become hydrated most of them will normally sink. This is perfectly normal. You can add one small drop of washing up liquid (dish soap) to the water beforehand to reduce the surface tension and this should ensure that all of your chilli seeds sink straight away. Seeds placed in sugar water will normally float because sugar water has a higher density than that of plain water.
I've even heard of some growers soaking wild chilli seeds in slurry made from frugivorous bird droppings and water. Frugivorous birds are the primary dispersal vectors for wild chilli seeds, and enzymes in their stomachs help with the germination process. However, if people see you collecting bird sh*t then you may get some odd looks! Some growers also place their chilli seeds in the refrigerator for several days prior to sowing them. The idea behind this is that the changes in temperature mimic the seasonal changes that some seeds encounter in the wild, and as a result it helps to awaken them from their dormancy and speeds up the germination time.
As an experiment, I once soaked some Trinidad Moruga Scorpion seeds in strong bleach for 12 hours, and although it did nothing to speed up the germination time, the seeds still germinated and grew into perfectly healthy plants. Incidentally, the seeds shown in the above photo were Chocolate Habanero seeds soaking in black tea. I soaked two batches in black tea and sowed one batch directly into the compost. The batch that was sown directly into compost was the first one to break through and it took 18 days to do so. The two batches soaked in black tea took 22 and 23 days. Perhaps they weren't very fond of Yorkshire Tea and would have preferred PG Tips instead.
How to Sterilise Seed Compost and Growing Equipment
Sterilising seed compost and growing equipment isn't strictly necessary and it may be considered as overkill by some growers, but it's something I always do. I believe that if something is worth doing it's worth doing correctly. Before sowing my chilli seeds I always sterilise the seed starting compost and all of the growing equipment that I'll be using, such as plant pots or seed trays, lids, plastic plant labels and heated propagator. By taking the time to ensure that everything is sterilised beforehand it may help to prevent headaches later on. There was a time when I didn't bother sterilising anything, and during those times if a bunch of seeds had failed to germinate it wasn't uncommon upon closer inspection to find small white larvae crawling around on some of the seeds. However, since I've been sterilising my seed starting compost it has no longer been an issue. If you can't be bothered to sterilise everything then at least sterilise the seed starting compost.
To sterilise compost for seed starting, measure out how much compost you'll need by filling up your plant pots or seed trays to the top and then transfer the compost mixture into an ovenproof vessel, such as an old casserole pan or baking tin. Don't forget that you'll also need to add extra compost which will be used for covering the seeds once they've been sown. Cover the vessel either with a tight-fitting lid or with aluminium foil and then place it into a preheated oven at 150C/300F for 1 hour. After 1 hour, remove the vessel from the oven, remove the lid or aluminium foil and then leave the compost to cool completely before using it. If you keep a busy schedule it may be an idea to sterilise your seed starting compost a day in advance.
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| Sterilised Seed Sowing Compost |
A mild bleach solution can be used to sterilise plastic plant pots, propagators, seed trays, lids and plastic plant labels. Fill a sufficiently sized bucket with warm water and stir in 1–2 tablespoons of bleach, depending on the size of your bucket. Add all of the growing equipment you plan to use and leave it in the bleach solution for a minimum of 20 minutes before removing it and giving it a thorough rinse under cold water. The same bleach solution can then be used to sterilise your heated propagator. Pour a sufficient amount into your heated propagator until it is filled to the top and then leave it for a further 20 minutes before pouring away the bleach and rinsing out your propagator with cold water.
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| Sterilised Plant Pots, Lids and Plant Labels |
There are many types of disinfectants you could use to sterilise your growing equipment. If you're lazy you could just spray everything with industrial strength isopropyl alcohol, but this would work out more expensive than using regular household bleach. Bleach is by far the cheapest option and it works perfectly well, probably better than most other disinfectants. Here in the UK, many old school gardeners used to use a disinfectant called Jeyes Fluid. However, as of writing this many of them no longer use it because the formula has now changed and the new product is not as effective. What was once a dark brown tar smelling disinfectant has now become a green pine smelling one. Don't waste your money on fancy products. Just stick to using regular household bleach. It's very cheap and is probably more effective than any of the disinfectants being marketed at gardeners. Just make sure you give everything a good rinse afterwards with plain water and you'll be good to go.
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| Bleach and Isopropyl Alcohol |
Although it's easy enough to sterilise small batches of compost in the oven when you're a small-scale grower like me, it's not a very practical thing to do when you're a large-scale grower. Growers sowing thousands of chilli seeds into compost would be at it all week! The only potting mixture I sterilise is the one I use for sowing seeds. I don't sterilise the potting mixture beyond that stage but I do still sterilise the various sized plant pots and water trays that I use throughout the growing season. I once purchased some chilli seeds that turned out to have come from a diseased plant and the subsequent plant grown from those seeds had either fungal or bacterial leaf spot. The symptoms of the disease didn't show up straight away, and when they did eventually show up all of my chilli plants were growing together in one place. When I noticed what was going on I destroyed the diseased plant and sterilised the plant pot it had been growing in. As luck would have it, the disease hadn't spread to any of my other plants.
If the plant pot had been reused straight away to grow another plant without being sterilised beforehand then there's a high chance that the same disease would have spread to the plant that was grown in it. Washing alone isn't enough to kill off diseases. From that point onwards, I've always sterilised all of my growing equipment from the seed sowing stage onwards, and again, bleach is my disinfectant of choice. At the end of every growing season I give all of my plant pots and water trays a good wash with hot soapy water and then I set them aside to dry before storing them away over winter. When it comes to using them again the following year they're already clean, they just need to be sterilised before use.
When Should I Start Giving My Chilli Seedlings Light?
Chilli seeds don't need light to germinate. It's only when the first seedling has broken through the compost that you'll need to provide your chilli seedlings with a light source, which can either be natural light or artificial light. I know for a fact that you can rely on natural daylight even in late January here in the UK because I've sown chilli seeds in mid-January before now and raised the seedlings in the front porch without using grow lights. However, the problem is that here in the Northern Hemisphere the days are still very short at that time of year, so your chilli seedlings won't grow very fast when all they have available is a few hours of natural light each day. Although I've written on this website in the past that I normally sow my chilli seeds anywhere between the beginning of January and the middle of February, I typically don't start them off until sometime during February. Given that most chilli varieties take at least seven days to germinate, by the time all of my seedlings have eventually emerged from the compost there is already an acceptable amount of daylight available to them, which just continues to increase from then onwards.
If you want a head start on the growing season you'll have much better results using grow lights. There are many types of grow lights available on the market, all of which range in price. Nowadays, LED grow lights tend to be the most popular ones and they are relatively cheap to run. Two other popular types of grow lighting are CFL (compact florescent lamp) and T5 tubes. When using grow lights it's important to also use a reflector to maximise the amount of light by increasing reflectivity. When using grow lights you'll need to run them for 16 hours per day (16 hours of light and 8 hours of darkness). Plants need a light and dark cycle to develop properly, and people often forget that darkness also plays an important role in plant growth.
I have a homemade grow light that I sometimes use when I sow my chilli seeds in January. I built it in 2011, and it consists of five batten holders fixed to a 30-inch by 5-inch piece of wood and a reflector made from cardboard. Three of the batten holders each hold a 30W CFL daylight bulb (6400K) and the remaining two each hold a 10W daylight bulb (6500K). In the past, I've also ran it with three 30W CFL daylight bulbs (6500K) and two 20W warm white bulbs (2700K). The inside of the reflector is lined with Mylar reflective sheeting and all five batten holders are wired together and ran from a single plug.
The batten holders are situated close together and the length of the grow light matches the length of my heated propagator. Although it doesn't meet the standards of today's professional LED grow lights, it has always worked well for getting a head start on the growing season and it is very cheap to run. It couldn't be used to grow a plant from seed to harvest, but it works perfectly well for raising small seedlings. In terms of colour temperatures, 6400K (daylight) is best suited for raising seedlings and for leafy growth because of its blue light output and 2700K (warm white) is best suited for flowering because of its red light output.
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| Homemade Grow Light |
When using grow lights you'll need to position them at the correct height above your seedlings. The correct height will depend on the strength of the grow lights you're using. You'll need to read the instructions that came with your grow lights or you'll just have to experiment and find out what works best for you. If you want to be meticulous you can purchase a handheld digital meter that can be used for measuring the light output around your plants. There are also apps available which claim to be able to do the same thing by making use of the light sensor on mobile phones. However, I've never used either one. If your seedlings look healthy and appear to be growing fine then you don't need to adjust the height of your grow lights. However, if they start growing leggy then you'll need to lower the lights accordingly. Legginess is caused by insufficient sunlight or artificial light that is too weak, dim or distant. As a result, the stems grow longer than normal because the seedlings are desperately trying to reach the light. Leggy seedlings can be rescued providing they haven't grown too leggy, and I'll show you how to do this further down the page.
Depending on the type of grow lights you're using, if you have them quite close to your plants you'll eventually need to raise them up as your plants start growing larger in order to keep the same distance between the lights and the top of your plants. If you notice the edges on some of the true leaves that are closest to the lights have started curling upwards then this is often an indication that the plants are receiving too much light. Typically, this only shows up on true leaves and rarely on seed leaves. This type of leaf curl can be caused by high-light stress or heat stress and is nothing to be overly concerned about. It's just the plant's way of reducing the amount of direct light on its leaves.
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| Leaf Curl on Chilli Plant Leaves Caused by Light Stress |
.jpg "Leaf Curl on Chilli Plant Leaves Caused by Light Stress") |
| Leaf Curl on Chilli Plant Leaves Caused by Light Stress |
Something else you may notice when the light is very intense is that the true leaves on some varieties may develop a purple pigment. This purpling is called anthocyanin pigment and is nothing to be concerned about. It's just a reaction that some varieties have to high-light stress. Not all varieties will do this though. The variety shown in this next photo with purpling on its leaves was Harold St. Barts. In both instances, all you need to do is adjust the height of your grow lights slightly by raising them up a couple of inches until you find the sweet spot. I should also mention that some chilli varieties naturally have purple leaves, and in most cases the seed leaves of those varieties are normally purple too.
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| Anthocyanin Pigment on Chilli Plant Leaves |
When raising seedlings and young chilli plants indoors under grow lights it's very important that you also provide them with adequate airflow and ventilation or it could result in some of your plants suffering from a condition called oedema. This is especially true if you have your plants growing in a cramped space, such as in an alcove, inside a grow box or on a shelf against a wall. Oedema isn't a disease, it's just a disorder caused by the plants taking up more water than they can transpire through their leaves, resulting in ruptured cells and unsightly looking leaves. At a glance, oedema looks a bit like small crystal deposits on the leaves.
As your chilli plants grow larger you should space them out to allow for better airflow between them. The best way to ensure there is good airflow between and around your plants is to point an oscillating fan at them for several hours each day. However, you only want a gentle breeze to make the leaves move, not a hurricane-force wind! This mimics the wind that plants are exposed to in nature and it also helps them to develop stronger stems. Wind also increases the transpiration rate in plants, so for this reason when using a fan you'll also need to keep a closer eye on the moisture level in the compost because you'll likely find that your plants will use up the available water at a faster rate.
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| Oedema on Chilli Plant Leaf |
Tip: If you've accidentally overwatered one of your beloved chilli plants and there isn't enough sun to dry up the compost as quickly as you'd like then the next best thing is to point a fan at your plant for several hours each day. The movement of the leaves increases the transpiration rate of the plant, which in turn causes the plant to use up the available water at a faster rate.
If the weather is good you can also make use of both natural and artificial lighting. During the occasions when I use grow lights I may move the plants into the porch on sunny days and then move them back under the grow lights again for 7–8 hours once it starts getting dark. However, you need to be very careful when doing this because exposing young tender seedlings or small plants to direct or indirect sun when they've been raised under artificial light can result in scorched leaves! This has never been an issue for me because during February and March the sun isn't very intense here in the UK. However, if the weather is very hot at that time of year where you live then by no means do I recommend exposing your chilli plants to direct or indirect sun until they've been hardened off properly. I'll touch on this more further down the page.
How Long Do Chilli Seeds Take to Germinate?
The length of time it takes for chilli seeds to germinate depends on several factors — how warm and how moist the compost is, what species of Capsicum you've sown and the age and the quality of the seeds, both of which will affect the viability. The compost has to have the correct amount of warmth and moisture for chilli seeds to germinate successfully. However, as a rule, you should start checking for signs of life after four days. Capsicum annuum, Capsicum baccatum and Capsicum frutescens varieties typically take between 7–10 days to germinate if the seeds are of good quality and the compost is warm enough and has the correct amount of moisture. Capsicum chinense and Capsicum pubescens varieties normally take a little longer to germinate.
Capsicum chinense varieties usually take between 10–21 days to germinate and Capsicum pubescens varieties around 10–14 days. However, the reason why I recommend checking for signs of life after four days is because I've known some varieties, even C. chinense varieties, to germinate in as little as four days, but I've never had any chilli seeds germinate in less than four days. Some Capsicum chinense varieties may take three or more weeks to germinate, and some wild Capsicum species may take two or more months to germinate. You just have to be patient. Something else which should also be taken into consideration is the age and the quality of the seeds. If the seeds are old or the quality is poor then the viability of the seeds will also be poor, or in some cases non-existent.
If your chilli seeds haven't germinated within the specified times written above then don't worry because it isn't set in stone. Sometimes, they may take longer. I once had some Chocolate Bhut Jolokia seeds that took over four weeks to germinate. However, if after three weeks there are no signs of life from your chilli seeds then it's always a good idea to sow another batch just in case the first batch fails to germinate. The main reasons for germination failure could be temperature related — too high or too low — moisture related — too little or too much — or poor seed viability. If you've had chilli seeds sitting on a shelf or pinned to a cork board for five or more years then there's a good chance that those seeds might not germinate. However, it's still worth a try. I once germinated some Orange Habanero seeds that were close to 10 years old and had been sitting in a cupboard for most of that time. It's fun to sow them just to see if anything pops up, but to play it safe you should also buy some new ones just in case.
Just to be annoying and pedantic, when seeds germinate in compost we don't really know when they've germinated because we can't see what's going on beneath the compost. When a seed germinates it first grows roots into the compost to access water. Once it has developed roots it starts growing shoots above the ground and then it sends a shoot to the surface and grows leaves to absorb light. In a process known as photomorphogenesis, the leaves then grow towards the light. Unless we are germinating seeds using rock wool cubes or germinating them on moist kitchen paper inside a zip lock bag then we really can't see when they've germinated.
How and When to Water Chilli Plants
When watering chilli plants that are growing in pots the key is to make sure that the growing medium always remains sufficiently moist, but not wet to the point where you could wring it out. When the potting mixture becomes too saturated it forces out the oxygen from around the roots, and the roots need oxygen in order for the plants to remain healthy. When growing chilli plants in pots the best way to check when your plants need water is to lift up the pots after applying water and to then make a mental note of how heavy they are. If the pots feel significantly lighter than when you last applied water then the chances are that your plants need watering again. This applies at all stages of growth; from the seedling stage right up to when you're plants are fully mature. However, just because one plant may be in need of water it doesn't mean that the rest of them will be. You need to check each of them on an individual basis.
The amount of water your plants use will depend on several factors — the weather, the environment, the pot size, the size of the plant and the root density. Once you get the knack of understanding the water requirements of your plants you'll soon learn to tell the difference between a chilli plant that has sufficient water and a chilli plant that has almost used up its water and is in need of replenishment. Checking the weight of the pots is a good way to learn when your chilli plants need watering. However, if you have hundreds of plants and some of them are growing in very large pots then it becomes an unrealistic way of doing things. Large-scale growers normally set up drip irrigation systems to take care of the water requirements of their plants.
Chilli plants that have recently been re-potted will use up the available water more slowly because they've not yet had chance to develop larger root systems into the new potting mixture. After re-potting your plants it could be a week or more before they need watering again, but once they start growing larger they will need watering more frequently. However, you should always check on a regular basis just to make sure. The weather plays a major role in how quickly plants use water. If you live somewhere like the UK, where the weather is unpredictable, your plants will need watering less often than if you live somewhere where the climate is much hotter, such as Australia or parts of the United States, where your plants may need watering on a daily basis during the summer months.
When the weather is hot and sunny your chilli plants will use water much faster than they will on cool and overcast days. Chilli plants growing in a sunny south-facing window will use water much faster than chilli plants growing in a polytunnel, greenhouse or outside in the garden. When grown indoors, chilli plants use water much faster than they do when grown outdoors. Not only is the environment different indoors but the extra warmth and intense sun coming through the window panes causes the water to evaporate much faster. You'll be surprised how quickly chilli plants can use up their available water when exposed to the sun. However, with practice you'll soon get the hang of it, but for the first few times you'll probably misjudge the weight of the pots and find that some of your plants run out of water and wilt as a result.
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| A Thirsty Chilli Plant |
New growers often panic when they discover that the leaves on one or more of their beloved chilli plants have wilted. In most cases, all it means is that those particular plants have run out of water. Chilli plants are very resilient and are much stronger than most people realise. Once you give your wilted chilli plants some water they will bounce back very quickly. Normally, within an hour they will be back to looking normal again. Some growers even do this intentionally to create water stress, believing that it will result in much hotter chillies due to the plants producing higher levels of capsaicin caused by the stress. Although it causes no real harm to the plants, you should always try and avoid letting your plants reach that stage if possible, especially when they're flowering. If you pay attention, you'll notice that your chilli plants use more water when they're flowering. You should keep the potting mixture moist at all times because it maximises the plant's ability to uptake nutrients. Plants need water in the potting mixture or soil in order to be able to use the nutrients that are available to them.
The amount of water that you should apply to your plants will depend on the size of the pots they're growing in. Don't just pour random amounts of water into the potting mixture because the chances are that you'll either be giving them too little or too much. There are two ways that people water chilli plants when growing them in pots. At some stage you may have heard about 'top watering' and 'bottom watering'. As both names suggest, top watering is when you pour water into the potting mixture and bottom watering is when you pour water into the water trays and allow the compost to soak it up. Personally, I use both methods.
My outdoor plants growing in the garden are always top watered because the pots are anchored to the ground, and so bottom watering isn't an option. However, all of my greenhouse plants and indoor plants are bottom watered, but I also top water them occasionally too. I should also mention that when growing chilli plants outside in the garden you should never place water trays under the pots because when it rains the trays will fill with water and then the compost will become saturated. It's best to allow the water to drain freely from the bottom of the pots, but if you have several days of heavy rain then you'll need to apply fertiliser again afterwards because most of what was is the potting mixture will have been washed away.
If you're new to growing chilli plants then I recommend you use the bottom watering method to begin with. The reason for this is because it's much harder to overwater your plants when using the bottom watering method. New growers who adopt the top watering method tend to just pour random, and often times very large, amounts of water into the potting mixture without paying attention to how much water they're applying. The water then passes through the potting mixture and the run-off sits in the water trays, where it remains without being poured away after a specified amount of time.
Instead, the best way is to pour water into the water trays and then leave it for 20 minutes. This is normally long enough for the potting mixture to soak up the correct amount. After 20 minutes, if there is any water still remaining in the trays it should be poured away. What happens when using the bottom watering method is that water is soaked up into the lower half of the potting mixture while the top half remains dry and well oxygenated. Many growers comment that their chilli plants always look much healthier when they use the bottom watering method.
The amount of water you should pour into the trays will depend on the size of the pots that your plants are growing in. If you start with a set amount of water and then measure the remainder left behind in the trays after 20 minutes you'll soon figure out how much to apply each time by subtracting the remainder from the start figure. The difference will then be how much water you should apply to each plant based on the size of the pot it's growing in. However, you don't have to be too meticulous about it. You can round the figure off. Once you work out how much water to apply you can then apply a set amount of water each time to all plants growing in the same sized pots, regardless of the species or the variety. It might seem odd, but when growing chilli plants in pots you need to be able to control the amount of water they receive. When using either the top or the bottom watering method, the key is not to apply larger amounts of water at once to plants that use more water, but instead to give the same amount of water each time based on the size of the pots the plants are growing in. This means that when it comes to watering plants that use more water they will just require watering more frequently than plants that don't use as much.
How and When to Fertilise Chilli Plants
When fertilising chilli plants some growers use water-soluble fertiliser and some use slow-release granular fertiliser. Water-soluble fertilisers are the ones sold as concentrated liquids or dry ingredients that you add to water. When using these types of fertilisers you measure out the specified amount of liquid or dry ingredients and then mix it into the specified amount of water. Slow-release fertilisers, also known as controlled-release fertilisers and continued-release fertilisers, are the type of fertilisers sold in granular form that you add to your potting mixture when re-potting your plants. When water enters the granules the fertiliser is slowly leached out into the surrounding potting mixture and then becomes available to the plants. This type of fertiliser is formulated to last for about six months and one dose per season is normally sufficient, but more can be added later if needed. Whether you use water-soluble fertiliser, slow-release fertiliser, organic fertiliser or synthetic fertiliser, your plants won't care.
To understand fertiliser a little more we must first take a look at NPK. You'll always see this trio of letters on all bottles and boxes of fertiliser and they are the chemical elements from the periodic table for the three primary macronutrients — nitrogen (N), phosphorus (P) and potassium (K). When you see this trio of letters on fertilisers it denotes the percentage or ratio of nitrogen, phosphorus and potassium that a given fertiliser contains. All three of these primary nutrients are essential for healthy plant growth. Nitrogen is a vital nutrient for photosynthesis and promotes leafy growth, phosphorus promotes healthy root development and flowering, and potassium, sometimes referred to as potash, regulates many metabolic processes required for growth, fruit and seed production. To simplify it, try to remember — (N) shoots, (P) roots, (K) fruits.
In order to remain healthy our beloved chilli plants also require calcium (Ca), magnesium (Mg) and sulphur (S), and these three nutrients are known as the secondary macronutrients. The other nutrients that our plants require, but in much smaller amounts, are boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo) and zinc (Zn), and these nutrients are known as the micronutrients. Unless there are sufficient amounts of all the aforementioned nutrients available in your compost, water or fertiliser then your chilli plants will become deficient. All good fertilisers will usually contain all of the micronutrients. Some may also contain all of the secondary macronutrients, but some may just contain added magnesium, perhaps because the manufacturers of said fertilisers assume that you'll be mixing them into tap water, which usually contains adequate amounts of calcium.
In regards to NPK, there is a difference between percentage and ratio. For example, a fertiliser sold as a high potassium fertiliser with an NPK value of 15-15-30 contains 15 percent nitrogen, 15 percent phosphorus and 30 percent potassium and it has an NPK ratio of 1-1-2, meaning it contains one part nitrogen, one part phosphorus and two parts potassium. An all-purpose fertiliser with an NPK value of 24-8-16 contains 24 percent nitrogen, 8 percent phosphorus and 16 percent potassium and it has an NPK ratio of 3-1-2. A balanced fertiliser with an NPK value of 10-10-10 contains 10 percent nitrogen, 10 percent phosphorus and 10 percent potassium and it has an NPK ratio of 1-1-1. Incidentally, a fertiliser with an NPK value of 10-10-10 is the same as a fertiliser with an NPK value of 20-20-20 or 30-30-30, the only difference is the concentration, meaning that the higher the numbers the higher the percentages of nitrogen, phosphorus and potassium it contains. Just like a fertiliser with an NPK value of 12-4-8 is the same as a fertiliser with an NPK value of 24-8-16, the only difference is that the latter is twice as concentrated.
There are many types of fertilisers available and the NPK values of them can become a bone of contention among growers. There are high nitrogen fertilisers, low nitrogen fertilisers, high potash fertilisers, all-purpose fertilisers, balanced fertilisers and plant specific fertilisers. Plant specific fertilisers are the ones which have been especially formulated to have an ideal NPK ratio for the types of plants they've been developed for, although when you cross-check some of them it becomes very clear that the manufacturers of said fertilisers don't agree on what the ideal NPK ratios are. Fertilisers that have been formulated for tomato plants can also be used for fertilising chilli plants. However, when using them to fertilise chilli plants it's generally recommended to only apply them at half strength.
When fertilising chilli plants I start out by using a dilute all-purpose fertiliser that has an NPK ratio of 3-1-2. I use this for several weeks, and once I've re-potted my plants into their final pots I then switch to using a fertiliser that contains one third more potassium to nitrogen. This has always worked very well for me. In my opinion, you don't need to be too selective when it comes to the percentage of phosphorus because chilli plants don't require large amounts of phosphorus and many commercially sold fertilisers already contain too much. A build up of phosphorus in the potting mixture can harm the plants and hinder their ability to uptake some of the micronutrients, namely iron and zinc.
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| Fertilisers |
In the early stages of growth, I fertilise my chilli plants once every 7–10 days. Once they've been re-potted into their final pots and I've switched to using a fertiliser that contains one third more potassium than nitrogen I then apply it twice weekly to most varieties. Small fruiting varieties are normally fine with just one application per week, whereas larger fruiting varieties perform much better with two applications per week. I always space out the applications and I always apply plain water at least once between each feed. This also helps to prevent a build up of salts in the potting mixture.
When using slow-release fertilisers (the ones you mix into your potting mixture) they can take a long time to break down so always read the instructions on the packaging before use. People would typically add about 5g per pot for smaller plants and 10–15g per pot for larger plants. Whenever I've used slow-release granular fertiliser for chilli plants I've only ever added it when re-potting the plants into their final pots. Instructions on how and where to add it have been given further down the page in the 'How to Re-Pot Chilli Plants into Their Final Pots' section.
When applying water-soluble fertiliser to your chilli plants you should only do so when they are ready to be watered, and you should only apply the same amount of fertiliser solution to your plants as you would water. For example, if you have a few plants growing in 10-litre pots and you normally give each of them 1-litre of water then this is also the same amount of fertiliser solution you should apply to each of those plants. Only when your plants are in need of water should you fertilise them. Don't just pick the same day each week to fertilise all of your chilli plants because chances are they won't all be ready for it. Just as all of your chilli plants may not need watering at the same time, then so too it is when fertilising them. Once your chilli plants have reached full maturity and have set the maximum amount of fruit and the fruit has reached its full size you can then stop fertilising them as often. From that point onwards, you can just apply it once every 14 days.
Avoid fertilising your chilli plants when they are just at the seedling stage because it's not necessary, and if you don't know what you're doing you could very easily burn them! Chilli seedlings don't need fertilising because the potting mixture already contains adequate nutrients to sustain them for up to six weeks. I only start fertilising my chilli plants about one week after re-potting them into their second pots. When it comes to fertilising plants it's always better to under-fertilise them than it is to over-fertilise them. If you apply too much fertiliser too often you will over-fertilise your plants and burn them. Always read the instructions on the fertiliser package before use, and if you're not using a plant specific fertilise that has been formulated for chilli plants and pepper plants then only apply it at half the recommended dosage to begin with. You can always increase the dosage later on if need be.
How to Sow Chilli Seeds
Before getting carried away and sowing lots of chilli seeds you first need to know how much space you realistically have available for your plants. This is also relative to pot size, which I'll discuss further down the page. Don't just sow seeds for lots of varieties and think you'll be able to grow them all on windowsills in small pots because it won't work out that way, unless, of course, you're growing dwarf varieties. A lot of new chilli growers get carried away with the amount of varieties they sow, and as a result they end up with far too many plants, which they find out later in the season when they don't have enough space to accommodate them all. Then again, this happens to many experienced chilli growers too! Unless you have a very large greenhouse or polytunnel then it helps to know the growth habits of your chosen varieties, and you can usually find this information quite easily online.
Anyway, it's now time to put things into action! To turn your chilli seeds into chilli plants that will eventually produce lots of wonderful spicy goodness we are first going to need plant pots or seed trays with tight-fitting lids, compost, water, plant labels, a marker pen and a heat source, such as a heat mat or heated propagator, which will be the heat source for germinating our chilli seeds. The type of potting mixture I use when sowing chilli seeds is similar to the one I use throughout the entire growing season, except I sieve the organic portion of the mixture to make it finer and I also sterilise the entire potting mixture.
The ratio of ingredients that I use in my seed sowing mixture varies slightly compared to the potting mixture that I use beyond the seed sowing stage. However, for the sake of this page and to keep things simple I'm going to recommend that you buy a bag of 'seed and cutting compost'. You can purchase seed and cutting compost from all good garden centres in the UK. Seed and cutting compost is basically a fine grade potting mixture that contains a gentle mix of minerals (meaning it's very low in fertiliser) and is specially formulated for sowing seeds and rooting cuttings.
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| Heated Propagator (left) and Heated Propagator with Lid |
Some brands of seed and cutting compost that I've tried contained lots of horticultural sand and some brands contained vermiculite, which helps with moisture retention and to some extent with drainage and aeration. Although it does inevitably help with drainage and aeration, the primary purpose of vermiculite is to help with moisture retention, which is important when germinating seeds. If you're new to growing chilli plants and have not yet had the chance to experiment with formulating your own seed sowing mixture then you should just use 'seed and cutting compost'. If you're in any doubt, just ask the staff at your local garden centre and they'll point you in the right direction. Here in the UK, most brands of multi-purpose compost can also be used for sowing seeds, and some brands even have this information written on the bag. However, just to play it safe, I recommend using seed and cutting compost when sowing your chilli seeds.
Just as a word of warning — never purchase cheap bags of seed and cutting compost from pound or dollar stores! There's a good chance that the quality will not be anywhere near as good as the quality of the ones sold at garden centres. I once purchased a cheap bag of seed and cutting compost from a pound store here in the UK, and when I opened it later that day I discovered that it was full of pine needles and chopped conifer leaves. Some people consider themselves to be poor growers, but the reality is that it may have more to do with the quality of the materials they use. It's a bit like someone learning to use a computer who goes out and buys a cheap laptop with poor specifications as opposed to buying a more expensive one with higher-end specifications. When the laptop starts playing up and crashing the person believes they're doing something wrong and eventually thinks about giving up. However, the reality is that the machine they purchased was of poor quality to begin with and it struggles to perform the tasks they want it to do, leading to an overall negative experience.
Whether you use plant pots or seed trays when sowing your chilli seeds, you'll need to be able to cover whatever you use with a tight-fitting lid of some description, but more on that a little later. When sowing my chilli seeds I sometimes use seed propagator trays with cell inserts, but I prefer to use plastic plant pots. The size of the pots I use varies depending on how many varieties I'm sowing and how much space I have available in the heated propagator. Sometimes, I use 3-inch pots and sometimes, when I only have a few seeds to sow of a given variety or when I'm running out of space, I use small 2-inch pots.
The problem when using seed propagator trays with cell inserts is that not all chilli varieties germinate at the same time. When using cell inserts and sowing multiple varieties per tray, some varieties will break through the compost much faster than the rest. By the time the latecomers have made an appearance the first varieties that broke through the compost will probably be in need of pricking-out or may have already been pricked-out. This ends up being a problem when you only have one heated propagator and one grow light because space quickly becomes an issue. When pricking-out seedlings and transplanting them into their first pots you then have to find room in your heated propagator for those seedlings, and if there are seeds in some of the cells that have still yet to germinate then you also have to keep the trays in the heated propagator too, which takes up a lot of space. Until those seeds germinate and the seedlings have grown to a size where they can be pricked-out, you may be stuck with a whole seed tray with only one or two cells in use.
Another issue I have is that I like to keep my plant pots and trays covered until the seedlings have broken through the compost, and when you have multiple varieties growing in one tray then this becomes a problem. What do you do when you need to remove the lid from the propagation tray for the first couple of varieties that have broken through the compost when the rest of the varieties have still yet to germinate? Rather than risk the compost drying up, I've cut some pieces of glass which I can use to cover individual cells. This allows me to cover cells which contain seeds that have still yet to germinate, whilst at the same time allowing me to remove the main lid from the propagation tray for the varieties that have already germinated. It ends up being very fiddly.
Get your artillery ready. You are going to need the following items to hand:
- Plant pots or seed trays with tight-fitting lids
- Seed and cutting compost
- Water
- Plant labels
- Marker pen
- Heat source
- Chilli seeds
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| How to Sow Chilli Pepper Seeds - Step 1 |
Fill your containers of choice to about a quarter of an inch from the top with your sterilised seed and cutting compost and then firm it down gently. Next, add a sufficient amount of water to ensure that the compost is well moistened — but not saturated! What you'll notice after adding water is that the compost level will sink down slightly. If you're using plant labels then I recommend inserting them into the potting mixture before sowing your seeds. Firstly, this ensures that you can correctly identify each variety when you're sowing multiple varieties at the same time, and secondly, it ensures that no seeds near the edges of the container are accidentally pushed down the sides when inserting the label. Whether you're using plant labels or stickers, it's very important to label each variety correctly. In the examples shown below I didn't insert a label because I'd run out of clear plastic lids for the small pot I was using. Instead, I had to use a piece of aluminium foil and then stick the label to the top.
Tip: If you're using plastic plant labels you don't need to buy new ones every year. You can just write numbers on the labels instead of names and then just assign a number to each variety.
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| How to Sow Chilli Pepper Seeds - Step 2 |
Place your chilli seeds onto the compost and try to space them out as best you can without placing any too near the edges. In the example shown below, I sowed six seeds, but I only intended on keeping one seedling. I always recommend sowing a few more seeds than you need so that you can pick the healthiest looking seedling(s) from the batch. Plus, it always pays to have a few spare seedlings just in case you accidentally damage any when pricking them out.
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| How to Sow Chilli Pepper Seeds - Step 3 |
Now that your seeds are in place, cover them with about half an inch of your sterilised seed and cutting compost and then firm it down gently. Add a little more water just to moisten the surface, but be careful not to pour it too quickly and don't add too much. Ideally, you should use a teaspoon or a spray bottle.
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| How to Sow Chilli Pepper Seeds - Step 4 |
Cover your containers with tight fitting lids to keep the moisture and warmth inside. If you're using seed propagation trays they may already have clear plastic lids, so just use those. If you're using plant pots, find something that fits snugly over the top, or alternatively just temporarily cover the pot with a piece of aluminium foil, which is what I used in the example shown below. Make sure that whatever you use is a good fit for the pots or trays. You don't want to use anything that leaves gaps around the edges or anything with holes in the top. You could even cover your trays or pots with a piece of glass, which is what I sometimes do.
The idea is to create a humid environment by trapping moisture and warmth inside. If you're using some type of plastic lid, like the one shown in the small thumbnail in the bottom right corner of this next photo, then make sure that it fits snugly on the inside of the pot so there are no gaps around the edges where moisture could escape from. You don't want to use anything with edges that overhang the pot because moisture could escape this way when the condensation runs down the sides. You don't want your compost to dry out at any stage from this point onwards.
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| How to Sow Chilli Pepper Seeds - Step 5 |
Your pots or trays should now be placed somewhere warm. For this, I use a heated propagator, but you can also use a heat mat. Anything that generates enough heat to maintain a steady temperature between 27–32C/80–90F will work fine. I've even heard of people using the underfloor heating in their bathroom to germinate chilli seeds, but I have no idea how well this actually works. Although chilli seeds will still germinate at temperatures below 27C/80F, they may take much longer to do so. If the temperature exceeds 32C/90F they may germinate a little faster, but the germination rates may not be as good.
I should also mention that when using a heated propagator or heat mat that these too should also be placed somewhere warm. Don't just place them outside in an unheated shed or greenhouse because they don't generate enough heat for that. They're heated propagators and heat mats, not radiators! If the place where they are being kept is cold then most of the heat they generate will be lost to the atmosphere. Also, if you loosely fill any empty space inside your heated propagator with scrunched up newspaper it will help to retain more heat.
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| How to Sow Chilli Pepper Seeds - Step 6 |
Providing you keep your plant pots or trays well covered you shouldn't need to add any additional water for the first week. The key to germinating chilli seeds is to maintain the correct temperature and moisture level in the potting mixture. After a week, if necessary, you can add some additional water just to maintain the moisture level, but chances are that you won't need to. You should keep your containers covered until you see signs of life. When pots or trays are left uncovered in a heated propagator or on a heat mat the potting mixture can dry up very quickly if you're not careful. One reason for this is because when sowing seeds we typically only use small volumes of potting mixture. The other reason is obviously because of the warmth being generated from the heat source. Remember, the seeds are not that far below the surface, so if you notice the surface of the potting mixture drying up then chances are that the moisture at seed level might not be much higher.
In the example shown below, my first Aji Mochero seedling took nine days to break through the compost. Like all seedlings, chilli seedlings are very delicate at this stage of growth and under no circumstances should you attempt to handle them straight away. The general consensus is that you should always wait until they have developed their first set of true leaves before pricking them out. However, once they reach a good size and look strong enough you can prick them out a bit sooner if you're careful. Even when the first seedling has broken through the compost, I still recommend keeping the pot or tray covered for about 24 hours, after which time you'll probably find that a few more seedlings have also broken through the compost.
I should also mention that if you temporarily covered your pots or trays with aluminium foil then you'll now need to remove it completely and switch to using something else instead. You'll need to use something that's clear and high enough to allow your seedlings to freely grow upright towards the light source. After 24 hours, you can remove the lid during the daytime, but depending on where your seedlings are being kept you may need to cover them again at night if low temperatures are likely to be an issue.
Once you start removing the lid on your seedlings you'll need to check them on a daily basis to make sure they have sufficient moisture. The best way to do this is by lifting up the pots and making a mental note of how heavy they are after applying water for the first time. As already mentioned, small volumes of potting mixture can dry up very quickly in a heated propagator or on a heat mat, especially when in a warm room under grow lights. Therefore, you may need to water your seedlings more often than you think. The same goes if your heated propagator is exposed to the sun. As a rule, in the early stages when seedlings have only just emerged and haven't yet developed proper root systems you may need to apply water every two or three days. If the potting mixture looks dry and the pots feel significantly lighter than since the last time you applied water then it won't hurt to give your seedlings some water.
This next photo shows the first of my Aji Mochero seedlings to break through the compost, and it took nine days to do so.
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| Aji Mochero Sprout - 3rd March 2024 |
After a further 24 hours, the first seedling that broke through the compost was beginning the process of growing upright towards the grow lights. You may notice that another two seedlings had also broken through the compost, giving a total of three seedlings.
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| Aji Mochero Sprouts - 4th March 2024 |
After 48 hours, the first seedling that broke through the compost had grown into the straight position and another two seedlings had also broken through the compost, now giving a total of five seedlings.
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| Aji Mochero Seedlings - 5th March 2024 |
After 72 hours, a total of five seedlings had broken through the compost, meaning that five out of the six seeds that were sown had germinated. Four of the seedlings were in the straight position and already looked strong enough to be pricked-out, but I waited another four days before doing so. As previously mentioned, the general consensus is to wait until seedlings have started developing their first set of true leaves before pricking them out, but I have to confess that I've never followed this rule and I've never killed any seedlings as a result. However, I've pricked-out more chilli seedlings than I care to remember and it's like second nature to me. If you're new to growing chilli plants then maybe you should wait until your seedlings have started developing their first set of true leaves before you go attempting to prick them out.
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| Aji Mochero Seedlings - 6th March 2024 |
Waiting until seedlings have started developing their first set of true leaves means that you should only prick them out when you see the first true leaf or pair or true leaves starting to develop between the seed leaves (cotyledons). Some people get confused and think it means they should wait until the first pair of full sized true leaves has developed on their seedlings before pricking them out. If you wait this long before pricking-out your seedlings you'll have a harder time doing so because by that point the seedlings and their roots will have become entangled. If you take a look at the first two photos in the next section you can see that one of my Aji Mochero seedlings had started developing its first set of true leaves. It's at that point when your seedlings should be pricked-out.
How to Prick-Out and Transplant Chilli Seedlings
After 15 days from the date of sowing my Aji Mochero seeds (on the 24th February) it was now time to prick-out my seedling of choice, which I've marked out with a red arrow in this next photo. It was the first one that broke through the compost and tenacity such as that should not go unrewarded! However, as you can see in these next two photos, all five seedlings looked equally healthy, so it really wouldn't have mattered which one I chose. It always pays to have a few more seedlings than you need, just in case you accidentally break any when pricking them out.
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| Aji Mochero Seedlings - 10th March 2024 |
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| Aji Mochero Seedlings - 10th March 2024 |
Before pricking-out your beloved chilli seedlings you'll first need a pricking-out tool, also known as a dibber. Pricking-out is the term used when separating seedlings and transplanting them into their first individual pots. Once seedlings are strong enough to be handled you should prick them out because doing so allows them to freely develop their root systems. As already mentioned in the previous section, if left together for too long in the pot or seed tray their roots will become entangled and they'll eventually become rootbound, and this will make the job of pricking them out and transplanting them much harder.
You can purchase a pricking-out tool online or from most good garden centres. This is a small narrow tool made from plastic, metal or wood. One end of the tool is tapered to a blunt tip and this is the end you're supposed to use when pricking-out your seedlings. Some growers don't bother using a dibber. Instead, they may use the handle of a teaspoon, an ice lolly stick or a blunt pencil. Personally, I've never purchased a dibber. I made my own pricking-out tool many years ago from a small piece of wood. It's important to use a tool that is tapered to a blunt edge or tip because it allows you to be more precise when working with delicate seedlings. Don't use anything that is sharp or too thick, such as a knife or a bamboo cane, because you may end up causing damage to your seedlings.
Personally, I don't like using anything metal when pricking-out seedlings, and the reason for this is because I once used the handle of a teaspoon to prick-out a few seedlings, and afterwards those seedlings appeared to go into a state of dormancy for a couple of weeks. However, seedlings of the same variety that were pricked out a day or two later using a wooden tool continued to grow as normal. I don't really know why this happened. My only guess is that maybe some metals retain a small electrical charge that plants dislike when it comes into contact with their roots.
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| Homemade Wooden Pricking-Out Tool |
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| Homemade Wooden Pricking-Out Tool |
When it comes to selecting plant pots to transplant your chilli seedlings into you shouldn't use anything too large. I always transplant my chilli seedlings into 3-inch plastic pots. The small 3-inch plant pots shown in this next photo are an ideal size for transplanting chilli seedlings into. Whatever size pots you choose to use, make sure they have plenty of drainage holes in the bottom. Plastic plant pots are by far the best choice. Avoid using terracotta pots because this will just make the job of re-potting your chilli plants much harder. You should also avoid using organic biodegradable plant pots made from such materials as peat or coir because these are no good for what you want. Just stick to using good quality plastic plant pots because then you can wash them out and reuse them. The green plastic plant pots shown in the photo below are over 15 years old. I bought them in 2009 for transplanting chilli seedlings into.
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| Small Green 3-Inch Plant Pots |
There are numerous brands of multi-purpose compost that can be purchased from UK garden centres. I don't recommend buying the cheapest brand you can find because there's normally a reason why it's cheap. Then again, I don't recommend buying the most expensive brand you can find either. I normally choose a brand that is in the mid-priced range. If you're in any doubt as to which brand to use then it never hurts to ask a few experienced gardeners what brands they currently recommend. Chilli plants need a well-draining potting mixture that has a pH value between 6.0 and 7.0. Whatever you do, don't make the mistake of purchasing ericaceous compost because this is formulated for acid-loving (lime-hating) plants and your chilli seedlings won't fare too well when transplanted in this.
I always add perlite to my potting mixture to help with drainage and aeration. I also add vermiculite to improve moisture retention. It's important that the potting mixture you make has good drainage and aeration. Chilli plants don't like growing in heavy or dense potting mixtures that stay wet for prolonged periods of time. However, this doesn't mean that your potting mixture shouldn't retain moisture. You want the potting mixture to remain moist but not soaking wet to the point where you could wring it out. Aeration is also important because plants need oxygen in the root zone in order to remain healthy and to develop healthy root systems. Some mass-produced brands of peat-free compost sold in the UK already have quite a coarse texture and this too will contribute towards the drainage and aeration in the potting mixture.
Many mass-produced brands of peat-free compost contain lots of horticultural sand and grit, and this should also be taken into account when deciding on how much perlite to use. When using compost that has a very fine texture, such as certain brands of peat-based compost, if you wish you can also add a small amount of horticultural sand to help prevent it from compacting together too much. This will also help to reduce water retention and will help with drainage. However, when using sand it's important that you only use horticultural sand because this type of sand is lime-free. If you use sand that contains lime then it will raise the pH of your growing medium. This is the only reason why gardeners add lime to soil in the first place, to raise the pH. Contrary to what some online sources claim, lime is not a reliable source of calcium for plants because before it can be used by plants it must first be broken down in the soil, and this process takes many years.
The amount of perlite and vermiculite that I add to compost tends to vary depending on the texture of the compost I'm using. If the compost has a coarse texture then I use less and if it has a fine texture then I add a little more. I use equal amounts by weight of both, and my starting point is 5g of each per 2-litres of compost. If you're using peat-free compost that already has quite a coarse texture then this amount will be fine. There are times in the past when I didn't use any perlite because the texture of the compost was already coarse enough. In all the years I've been growing chilli plants I've never used much perlite or vermiculite in my potting mixtures. Some growers tend to get carried away with the amount that they use. If you take a look at the next photo you can see that I really don't use much of either in my potting mixture.
I should also mention that it is possible to add too much perlite and vermiculite or any other inorganic materials to your compost. A number of years ago I saw information online stating that perlite should always make up one-third of the potting mixture when growing chilli plants, so I decided to do an experiment and put it to the test. I grew four plants in a potting mixture that was comprise of one-third perlite, which was much more perlite than I'd ever used before. Not only did those plants take longer to become established, but at the end of the growing season when I took them down I noticed that the root systems on all four of them were not as good as the root systems on the plants that were growing in a potting mixture containing much less perlite. Think about it, the more inorganic material you mix into your potting mixture the less organic material it will contain. Another thing I see some growers adding to their potting mixture is magnesium sulphate (MgSO4), commonly known as Epsom salts. Epsom salts are very water soluble and they will be washed out of your potting mixture in no time at all.
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| Potting Mixture Containing Perlite and Vermiculite |
Perlite is made by heating a type of naturally occurring volcanic glass to extremely high temperatures of around 1000C, after which it expands to many times its original size. Horticultural perlite is a lightweight, micro-porous material that is white in colour and resembles polystyrene granules. It is sold in fine grade, medium grade and coarse grade, and its primary usage in horticulture is to provide drainage, aeration and to help prevent compost from compacting together too much. Due to its micro-porous nature, it also has some moisture retaining qualities. Fine grade perlite will contribute more towards moisture retention due to its smaller particle size, whereas medium grade and coarse grade perlite will contribute more towards aeration due to their larger particle sizes, which create air pockets in the compost. The larger the particle sizes the more effective it will be at providing aeration. Perlite is an excellent addition to any potting mixture for plants requiring a well-draining growing medium.
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| Perlite |
Vermiculite is made from a naturally occurring clay mineral that is mined in various places around the world, including South Africa and parts of the United States. The extracted mineral is processed to remove impurities and is then heated to extremely high temperatures of around 1000C, after which it expands to many times its original size. The resulting product is a lightweight and highly absorbent material, which varies in colour from dark grey to sandy brown. It has a high cation exchange rate, a neutral pH and its primary usage in horticulture is to aid with moisture retention. Inevitably, it also helps with drainage and aeration and is particularly useful in potting mixtures that are used for sowing seeds due to its moisture retaining qualities. When sowing seeds, instead of covering them with a fine layer of compost some growers prefer to use a layer of vermiculite instead.
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| Vermiculite |
Horticultural sand is a very gritty type of sand that consists of both large and small particles and is typically made from crushed quartz, crushes granite and crushed sandstone. It is lime-free, meaning it won't affect the pH of your growing medium, and its primary usage in horticulture is to break up clay soils or heavy soils, to prevent potting mixtures from compacting together too much, to reduce water retention and to help with drainage. If you choose to add horticultural sand to your potting mixture then you don't need to add very much. Whenever I've used sand in any of my potting mixtures I've never added any more than two teaspoons per 2-litres of compost. However, if you're using peat-free compost that already has quite a coarse texture then you won't need to add sand. Horticultural sand is not the same as playing sand. Playing sand consists of much smaller particles. Whatever you do, never collect sand from the beach because you don't know what it contains and it may also contain salt, which will kill your plants!
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| Horticultural Sand |
The best time to prick-out and transplant seedlings is in the evening after the sun has set or at night just before switching off the grow lights. This gives them a good few hours of darkness which they can use to recuperate.
Before you start pricking-out your chilli seedlings you're going to need the following items to hand:
- Plant pots
- Pricking-out tool (dibber)
- Potting mixture
- Water
- Plant labels
- Marker pen
- Heat source
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| How to Prick-Out Chilli Pepper Seedlings - Step 1 |
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| How to Prick-Out Chilli Pepper Seedlings - Step 2 |
Before pricking-out your seedlings you should first give them some water and then wait for a few minutes. This will help to loosen up the compost. If they are growing in small plastic plant pots like the one shown in this next photo you can also give the pot a gentle squeeze to help loosen things up further. After a few minutes, insert your pricking out tool down the side of the container into the compost and gently lift up the first seedling. Take your time when doing this. The key here is to be as gentle as possible in order to cause the least amount of damage to the roots.
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| How to Prick-Out Chilli Pepper Seedlings - Step 3 |
Using your pricking-out tool, carefully lift out the seedling whilst gently holding one of the seed leaves between your finger and thumb. Don't just pull the seedling out of the compost by one of its leaves because you will break it. Let the pricking-out tool do the work, and never hold the seedling by its stem. Seedlings will grow new leaves but not a new stem. Also, try not to handle the roots if possible. If you see a few pieces of root still remaining in the old pot after lifting out your seedlings then don't be too alarmed. If you've never pricked-out seedlings before then you can't be expected to do it perfectly the first time. Providing your seedlings still have roots, even if a few pieces have broken off, they will still continue to grow. In fact, there have been occasions when I've accidentally broken the whole root off of some seedlings, and in such cases they still continued to grow perfectly fine without even so much as wilting. They grow new roots very quickly.
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| How to Prick-Out Chilli Pepper Seedlings - Step 4 |
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| How to Prick-Out Chilli Pepper Seedlings - Step 5 |
When transplanting chilli seedlings into their first individual pots you should also bury a good portion of the stem into the compost. It might seem odd, but doing this helps to stabilise them and it stops them from toppling over. It's also the way to fix leggy seedlings. New roots will grow from the part of the stem that has been buried into the compost. If you wish, you can bury them so that the seed leaves are just above the compost, which is what I always do.
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| How to Prick-Out Chilli Pepper Seedlings - Step 6 |
Whilst still holding on to one of the seed leaves, gently fill in the hole around the stem as best you can using your pricking-out tool. You don't need to add additional compost, just push some of the compost into the hole. You don't have to be too meticulous about it because once you add water it will help to push compost into any remaining spaces. After transplanting the first seedling don't forget to re-insert the plant label from the old pot or seed tray, and if you plan on keeping more than one seedling of a given variety then remember that you'll also need to write out additional labels so that you can identify each variety correctly.
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| How to Prick-Out Chilli Pepper Seedlings - Step 7 |
As soon as you've transplanted your chilli seedling you should water it straight away. You should wet the entire surface of the compost and you should also apply a generous amount of water next to the stem to ensure that it goes straight to the roots. When applying water next to the stem you should also keep hold of one of the seed leaves whilst pouring it just to prevent the seedling from accidentally being washed further down into the hole. Sometimes, the transplant holes may be a little deeper than required, but this is fine. You'll only need to do this when watering them for the first time. What you may also find when applying water is that the compost around the stem of the seedling may sink down slightly on one side. This will happen if the water has pushed some of the compost into any remaining spaces left behind after making the transplant holes. In such cases, all you need to do is add another pinch or two of your potting mixture to fill in the gap until it looks even with the rest of the surface.
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| How to Prick-Out Chilli Pepper Seedlings - Step 8 |
Once your seedling has been watered-in transfer it back into your heated propagator or on to your heat mat. If low night time temperatures are likely to be an issue then you should keep your seedlings warm by covering them at night with a clear lid, such as the clear plastic cups shown in this next photo. Transplant shock will not be an issue providing you water your seedlings straight away after transplanting them and that you keep them somewhere warm. The only time I've ever had seedlings suffer from transplant shock was when I pricked-out about 50 of them at once and didn't water any of them until I'd finished. By the time I'd finished transplanting the last ones some of the first ones had collapsed. However, after applying water the ones which had collapsed soon perked back up again. As mentioned in step 1, if you're planning to prick-out and transplant lots of seedlings at once, then to save time you'd be better off wetting the compost prior to making the transplant holes, but just to ensure that the roots are nice and moist you should still apply water next to the stem of every seedling once you've finished.
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| How to Prick-Out Chilli Pepper Seedlings - Step 9 |
Any remaining seedlings that you have can be pricked-out and transplanted in the same way and then given away as gifts to friends or family. Failing that, you'll just have to put them on your compost pile or into your next stir fry.
.jpg "Aji Mochero Seedlings - 10th March 2024") |
| Aji Mochero Seedlings - 10th March 2024 |
You'll be surprised how quickly chilli seedlings grow once they've been pricked-out and transplanted into their first individual pots. These next two photos show my Aji Mochero seedling 12 days after being transplanted into its first pot. During that time it had been watered about four times. It gets quite warm under the grow lights in the heated propagator. You may also notice that there was a small amount of leaf curl on a couple of its true leaves. This was just a reaction to the high-light intensity under the grow lights. The rest of the chilli plants in the heated propagator weren't suffering from leaf curl, so I didn't adjust the height of the grow lights just for this one variety.
Although the potting mixture looks dry in these next two photos, all of the chilli plants had been watered the previous evening, so only the top portion of the potting mixture was dry. There was still sufficient moisture further down in the pot. The warmth from the grow lights dries up the top portion of the potting mixture quite quickly. As already mentioned, the best way to tell when your chilli plants need water at any stage of growth is to lift up the pots after applying water and to make a mental note of how heavy they are. When the compost looks dry and the pots feel significantly lighter then it's time to apply more water.
When watering chilli seedlings at the stage of growth shown in the above photos I don't give them very much. I apply enough to wet the entire surface of the compost and then I also pour some at the base of the stem, just as I do when transplanting them. However, when watering them at the stages of growth shown in the photos below I give them a bit more. What you'll notice in the photos below is that the compost level has sunk down in the pot by about a centimetre. When watering them at these stages of growth I normally apply sufficient water to fill the pots to the top and then I let it soak through the compost and allow the excess to drain out from the bottom. By allowing the compost to dry up slightly between waterings it helps the plants to develop stronger root systems because they grow more roots to go in search of water.
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| Aji Mochero - 22nd March 2024 |
.jpg "Aji Mochero - 22nd March 2024") |
| Aji Mochero - 22nd March 2024 |
After a further 16 days (28 days after being transplanted) my Aji Mochero seedling had grown significantly and was now a small plant that was almost ready to be re-potted into its next sized pot. "They're lovely at this age, aren't they? It's when they grow up and become teenagers that they become a pain in the ar*e!" 😁
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| Aji Mochero - 7th April 2024 |
At this stage of growth my chilli plants have either been raised in the porch using natural light and are already accustomed to the sun or if raised under grow lights they have been spending the day in the front porch before being moved back under the grow lights for a few hours each evening. In the case of the latter, the benefit to doing this is that my plants gradually become accustomed to a different and more varied environment than the one they experience when under grow lights. They are exposed to warmer and colder temperatures and they are also exposed to the sun, which isn't very intense in the UK in early April. This is the start of a process known as hardening off, which I'll touch on more in the next section. My chilli plants stay in the heated propagator until they are re-potted into their second pots and then they are moved into the front porch because space becomes an issue and there is nowhere else for them to go.
As mentioned in the fertiliser section, I don't fertilise my chilli plants at the stages of growth you see in this section. There really isn't any need because multi-purpose compost already contains sufficient fertiliser to feed your plants for about six weeks. I should also mention that bottom watering your chilli plants at this stage of growth is not ideal. When bottom watering at this stage of growth most growers would put several plants into one tray and then fill the tray with water. The problem with this is that some pots may soak up more water than others and you need to be able to control the amount of water that your chilli plants receive at all stages of growth.
How to Re-Pot Chilli Plants
Six days later, my small Aji Mochero plant had reached a good size and it was now ready for a larger pot. "Come on, little one, it's time for some new shoes." 😆
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| Aji Mochero - 13th April 2024 |
The general consensus among chilli growers is that when re-potting your plants you should ideally choose a plant pot that is roughly twice as large as the current pot, although you don't have to be too meticulous about it. However, you are supposed to increase the pot sizes incrementally before re-potting your plants into their final pots. The reason for this is because the plants perform better when doing so. The amount of times you'll need to re-pot your chilli plants before re-potting them into their final pots will depend on the size of your final pots. As a rule, most of my chilli plants are grown in 5-litre or 7-litre pots, and therefore I only go up one more pot size before re-potting them into their final pots. However, some of my plants are grown in 10-litre or 12-litre pots, and in such cases I go up two more pot sizes before re-potting them into their final pots.
When re-potting my chilli plants into their second pots I use a pot size of around 1.5-litres. This is an ideal size for a second pot. For plants that are going to be grown in a final pot size of either 5-litres or 7-litres the next sized pot for those plants will be their final pot. However, plants that are going to be grown in a final pot size of either 10-litres or 12-litres will be re-potted again into 5-litre pots before eventually being re-potted into their final pots. Doing it this way has always worked very well for me.
Re-potting chilli plants isn't rocket science. Some growers just partially fill the next sized pot with their potting mixture of choice, remove the plant from its current pot, place the root ball into the centre of the partially filled larger pot and then fill around the edges with more potting mixture. This is the method most growers use, and when you have lots of plants to re-pot at once then it's also the fastest method. However, there is another method for re-potting plants, and it's one that allows you to know whether or not you have enough potting mixture made up beforehand for all of the plants that you're planning to re-pot. It's the method I always use when re-potting my chilli plants at all stages of growth. In terms of the potting mixture, if you're happy with the mixture that you used when transplanting your seedlings into their first individual pots then you can continue to use the same potting mixture throughout the entire growing season.
Before you start re-potting your chilli plants you are going to need the following items to hand:
- Plant pots
- Potting mixture
- Water
Place a sufficient amount of your potting mixture into the next sized pot until it's about three-quarters full, and then make a hole in the centre with your hand. Place into the hole an empty pot of the same size and shape as the one the plant is currently growing in, and then push it down slightly until the top of the smaller pot is level with the top of the larger pot. Now, just fill around the edges with more potting mixture and then firm it down slightly until everything is even. You don't need to press down too hard; just enough to ensure that there are no empty spaces.
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| How to Re-Pot Chilli Pepper Plants - Step 1 |
Once you've firmed down the potting mixture between the two pots and everything looks even, you'll then be able to carefully remove the smaller pot without the compost collapsing, leaving behind a hole of the same size and shape as that of the pot which your plant is currently growing in, as can be seen in this next photo.
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| How to Re-Pot Chilli Pepper Plants - Step 2 |
Next, remove your chilli plant from its current pot and then gently drop the root ball into the hole in the centre of the larger pot. To remove the plant from its pot, gently squeeze around the edges of the pot a few times, and whilst gently holding onto your plant, carefully turn it upside down and tap the bottom of the pot a few times until the root ball drops out. Sometimes, this may take a while, so you'll just have to persevere.
If the root ball happens to come out partially intact then don't worry. All you have to do is place a sufficient amount of your potting mixture into the hole to ensure that when you drop the root ball into the hole that the top of it is sitting flush with the surface of the compost in the larger pot. However, providing you water your plants before re-potting them and you take your time then it shouldn't be an issue.
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| How to Re-Pot Chilli Pepper Plants - Step 3 |
After gently dropping the root ball into the hole, place a little more potting mixture on the top and then level off the surface, as can be seen in this next photo.
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| How to Re-Pot Chilli Pepper Plants - Step 4 |
Don't forget to re-insert your plant label so that you can correctly identify each variety later on. Forgetting to do so is an easy mistake that anyone can make.
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| How to Re-Pot Chilli Pepper Plants - Step 5 |
Your newly re-potted chilli plant should now be given some water. Adding water will help it to overcome any stress from being re-potted. I give my newly re-potted chilli plants enough water until I see a small amount of run-off. You should also apply a fair amount of water near the base of the stem because until they've had chance to root into the new compost this is where their roots currently are.
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| How to Re-Pot Chilli Pepper Plants - Step 6 |
Here was my Aji Mochero plant after being watered-in. If you live in the UK or somewhere with a similar climate, the chances are that you won't need to water your plants again for another week or so, although you should still check before then just to make sure. Once your plants grow larger and develop denser root systems they will require water on a more frequent basis.
.jpg "Aji Mochero - 13th April 2024") |
| Aji Mochero - 13th April 2024 |
Using this re-potting method is easy once you get the hang of it, and as already mentioned it allows you to know whether or not you have enough potting mixture made up beforehand for the amount of plants that you intend to re-pot. You can fill as many plant pots as you need and then all you have to do is remove each plant from its current pot and gently drop the root ball into the hole. The Aji Mochero plant shown in the photos above was re-potted at the same time as eight other plants. Regardless of how many times you need to re-pot your chilli plants and regardless of the pot sizes, the process is the same, as you'll see in the next section. However, once your plants have grown larger they are going to need canes for support, which I'll touch on in the next section. As already mentioned, most of my plants are grown in a final pot size of either 5-litres or 7-litres, and it's at that stage, once they've been re-potted into their final pots, when I insert canes because they are normally fine without them until then.
If you intend on using a final pot size that is larger than the aforementioned two and you plan to re-pot your chilli plants again before eventually re-potting them into their final pots then at some stage you are going to need a cane for support. When I grow Rocoto plants outside in the garden I use a final pot size of 12-litres, so before re-potting them into their final pots I first go up another pot size and re-pot them into 5-litre pots. Once they've been re-potted into 5-litre pots it's at that stage when I insert a cane for support. It really depends on the growth habits of the plants you're growing, and I'll touch on this in the next section.
After being re-potted your chilli plants may not appear to do much growing for about 7–10 days. This is because their energy is being focused on developing larger root systems. What you may notice after a day or two is that the plants will appear to spread their leaves out a little, and this is probably a response to the extra root space. After 7–10 days, you may start seeing roots poking through the drainage holes in the pots, and after this time you'll start noticing significant growth above the compost too. It's important that you keep checking to see if your chilli plants need water, and as already mentioned, the best way to do this is to pick up the pots and make a mental note of how heavy they are after watering them. When the compost looks dry and the plants feel significantly lighter then it may be time to apply more water.
Once my chilli plants have been re-potted into their second pots they are then moved into the front porch on a permanent basis until eventually being re-potted into their final pots and placed into their positions for the growing season. Some of them are grown indoors in windows and in a porch, some are grown outdoors in the greenhouse and some are grown outside in the garden. Due to the fact that my chilli plants are already accustomed to varying temperatures and indirect sun, either because they were raised in the porch using natural light or because they were raised under grow lights and then gradually became acclimatised to varying temperatures and indirect sun because they spent their days in the porch instead of under the grow lights, they can be safely moved into the porch at this stage without any issues.
It's very important that your chilli plants are hardened off properly before being exposed to direct sun or even indirect sun through a south-facing window, porch, conservatory or greenhouse. Exposing your chilli plants to direct or indirect sun without hardening them off properly beforehand will probably result in the leaves on your plants becoming sun scorched. Depending on the severity of the sun scorch, the damaged leaves may drop off a day or two later leaving you with plants that look like they have alopecia! They will eventually grow new leaves, but it will set their growth back by a few weeks.
I once had a Chocolate Habanero plant growing in a southeast-facing window and it was doing really well. One morning, I decided in my wisdom to place it outside for the day in direct sun, and when I checked on it later that evening all of its leaves had wilted and were badly sun scorched. About 24 hours later, nearly all of the sun scorched leaves had fallen off. Even when you have plants growing in windows that can take intense indirect sun through the window pane, if you expose them to more intense conditions than what they're used to then they too can also be scorched. This next photo shows what sun scorched leaves look like on a Capsicum pubescens plant. This wasn't a severe case, and fortunately the plant in question didn't lose any of its leaves.
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| Sun Damaged Leaves on Capsicum Pubescens Plant |
Hardening off means gradually getting your plants acclimatised to the environment they'll be growing in throughout the growing season before eventually moving them into their permanent positions. If you've raised your plants using natural light then this is less of an issue because they will already have become accustomed to the sun, and in many cases varying temperatures. However, if you've raised them under grow lights then they will need to be hardened off properly first. The environment under grow lights is very different compared to the one they'll eventually be growing in. In most cases, when plants are raised under grow lights they've never even been exposed to the sun. When people raise plants under grow lights they normally do so in centrally heated houses where the plants don't experience very much in the way of temperature variations either.
The only reason why we raise chilli seedlings early under grow lights is to lengthen the growing season. Some Capsicum species require a longer growing season than others, namely C. chinense and C. pubescens, and so this is especially important for people living in colder parts of the world where the growing season in much shorter. However, eventually some of those plants that were raised under grow lights are going to be moved into greenhouses where the environment is very different compared to the one they are accustomed to when under grow lights. Some plants may also be moved outside into the garden where they will also be exposed to wind and rain. Even small plants that are going to be grown indoors in windows will still need to be acclimatised to the sun before being moved into their permanent growing positions because during the summer months when it gets very hot they will be exposed to intense indirect sun through the window panes.
When hardening off chilli plants that are going to be grown in greenhouses or outside in the garden you should start about 3–4 weeks before you plan on moving them into their permanent growing positions. Although you can harden them off in any sized pot, it's much easier to do when they're still in smaller pots because it means you have less to carry. You should start hardening off your chilli plants when the daytime temperatures are around 55–60F, which is roughly where they'll be in UK greenhouses in April. Start by placing your plants in a shaded spot in your greenhouse for a couple of hours. If you don't have a shaded spot you can create one by placing them under a table or bench. If the weather is overcast you don't need to place them in a shaded spot, but for the first three or four days it's important that you don't expose them directly to the sun.
After a couple of hours, you should then take your plants back indoors. Repeat the same process every day, and after three or four days you should expose your plants directly to the sun for about 20–30 minutes before moving them back into the shade. This is best done in the morning or late afternoon when the sun isn't as intense. Every day, you should gradually increase the length of time that your plants remain in the greenhouse and you should also increase the amount of sun exposure they receive by about 20–30 minutes. Eventually, over a 3–4 week period your plants will be able to remain in the greenhouse all day and will also be able to take full sun exposure without any issues. However, you still need to be careful if the sun is particularly intense.
Once the night time temperature remains above 55F you can leave your chilli plants in the greenhouse on a permanent basis, but if the temperature drops below this then you'll still need to bring them back indoors at night. In the early part of the growing season you'll need to keep a very close eye on the weather forecast. If there's a threat of very low temperatures or frost looming on the horizon then you'll definitely need to move your beloved chilli plants back indoors overnight because a frost could easily kill them.
Chilli plants that you plan on growing outside in the garden should be treated the same way as those that you plan on growing in a greenhouse. The only difference is that after about two weeks, instead of leaving them in the greenhouse with the rest of your plants you can move them outside for a few hours each day providing the wind isn't too strong. Although they will eventually be exposed to wind, you don't want them to get blown over and damaged in the meantime. You should avoid exposing them to the rain until they've been re-potted into their final pots and moved into their positions for the growing season, by which time the temperatures will have increased. When hardening off chilli plants that are to be grown indoors the same method applies. The only difference is that you just need to perform the process indoors instead of moving your plants outdoors into the greenhouse. Hardening off is a gradual process and one that requires patience.
I should also mention that before moving your chilli plants back indoors from the greenhouse you need to check them thoroughly to make sure that no aphids or any other critters are planning to hitch a ride. If this happens they could easily spread to any indoor chilli plants that you may have. When your outdoor plants have reached the stage of growth where they spend all day in the greenhouse, if you ever need to take them back indoors overnight due to low temperatures then you should always keep them completely separate from any indoor plants that you may have.
These next two photos show my Aji Mochero plant 32 days after it was re-potted into its second pot. As you can see, it was looking nice and healthy and had grown significantly. It was almost ready for its final pot of the growing season. I'll touch a bit more on final pot sizes in the next section.
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| Aji Mochero - 15th May 2024 |
.jpg "Aji Mochero - 15th May 2024") |
| Aji Mochero - 15th May 2024 |
When hardening off your chilli plants in a greenhouse, if you notice that the leaves have turned from lush green to pale green or pale green with a slight yellow hue then the likely culprits are low temperatures, too much water or a combination of both. When moving your plants from under grow lights in a warm room into a greenhouse where the temperatures are lower it will inevitable cause some stress to your plants. The pale leaves are normally caused by a stress reaction to low temperatures. This is why when hardening off your chilli plants it should be done as a gradual process over a 3–4 week period. Too much water in the potting mixture can also cause the leaves on your plants to turn pale, but early in the season when the outdoor temperatures are still quite low it's normally caused by low temperatures.
Early in the growing season, when your plants are exposed to greenhouse temperatures the potting mixture won't dry up as quickly as it will when they're grown in a warm room under grow lights. For this reason, you may find that the more time your plants spend in the greenhouse the less water they will use. However, once the weather starts warming up this will change. The key to preventing the leaves on your plants from turning pale is to correctly manage the amount of water they receive and to keep a close eye on the temperatures, especially the night time temperature! As already mentioned, the night time temperature shouldn't drop below 55F. If you notice the leaves on some of your plants have turned pale then just allow the potting mixture to dry up slightly before watering them again.
How to Re-Pot Chilli Plants into Their Final Pots
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Before deciding on what your final pot sizes are going to be you first need to know a few things: A) where your plants are going to be grown, B) the growth habits of your chosen varieties, and C) how much space you realistically have available for them. Remember, the larger the pot size the larger the plant. Even familiar varieties that have manageable growth habits when grown in 5-litre or 7-litre pots will grow into much larger plants when grown in 10-litre pots. Re-potting your chilli plants into pots that are too large for the spaces you have available will result in monster plants and a headache later on! Take it from me, a windowsill farmer with over 15 years experience.
If you're planning to grow your chilli plants in a sunny window then your final pot size should be no larger than 7-litres, but 5-litres is a more realistic size. It just depends on the growth habits of your chosen varieties because they're all different. If you're planning to grow varieties that you're unfamiliar with in windows you should only use a final pot size of 5-litres. Once you've become familiar with their growth habits you can then try growing them in larger pots the following year. However, midway through the growing season you'll probably be glad that you only used a final pot size of 5-litres.
For example, Peruvian White Habanero is a variety I'm very familiar with. It has a compact bushy growth habit and it grows very well for me in southeast-facing window in a 7-litre pot. When grown in 7-litre pots the plants grow to a manageable size and produced a respectable amount of chillies. However, one year I decided to do an experiment and I re-potted one of the plants into a 9-litre pot just to see how much bigger it would grow in the window. Even though the pot was only 2-litres larger than the one I normally use, the result was a much larger plant, and due to the extra size it became much harder to manage when grown in a window.
I was still able to grow the plant in the window without it growing leggy, but I wouldn't do it again. Bigger isn't always better! What you have to consider when growing chilli plants in windows is that they only receive light from the front. This isn't a problem when your plants grow to a manageable size and you're able to provide them with adequate light. However, when you re-pot them into pots that are too large your plants will inevitably grow much larger, and when this happens, being able to provide them with adequate light through a window becomes much more of a challenge. I'll touch on this more in the next section.
I've successfully grown many chilli varieties in windows in both 5-litre and 7-litre pots. However, when growing them in the porch or outdoors in the greenhouse I normally use a final pot size of 7-litres. This is because when grown in a porch, conservatory or greenhouse there is more space available and more light. When plants are grown in the aforementioned places they receive light from the sides and from above, as opposed to just from the front when grown in windows. If you have a large enough porch, conservatory or greenhouse you can use a final pot size that's larger than 7-litres. However, you also need to make sure that there's adequate space between your plants so that the light can penetrate through and reach them all. There also needs to be good airflow. You don't want your plants growing together in a cramped space because if they don't receive adequate light you'll end up with a dense green jungle and much less fruit!
Most chilli plants can be grown successfully in 5-litre pots if space is an issue. If space isn't an issue then growing them in smaller pots means you can also grow more plants and try more varieties just to see which ones you prefer. Capsicum annuum varieties will grow well in 5-litre pots, and so too will Capsicum baccatum varieties. There are some dwarf varieties belonging to the C. annuum species, such as Prairie Fire, that don't benefit from being grown in 5-litre pots because they only grow to a certain size. If you're growing any of these then you should only aim for a final pot size of around 3-litres. Anything larger is just a waste of space.
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| Capsicum Annuum - Jalapeño M (left) and Malawi Birds Eye |
When growing Capsicum baccatum varieties in windows you should never use a final pot size larger than 5-litres or the plants will grow too large. Ideally, when growing C. baccatum varieties in a window you should use a final pot size of around 4-litres. Most varieties belonging to this species tend to have gangly growth habits, and re-potting them into large pots when growing them in windows means you'll end up with a triffid! However, given their prolificacy you'll still end up with chillies. C. baccatum varieties don't make very good candidates for window growing due to their growth habits. However, pruning them occasionally with a scissors will help to keep them under control.
I've successfully grown Aji Lemon and Inca Berry in windows in both 4-litre and 5-litre pots. Some varieties belonging to the C. baccatum species can grow very tall, such as Bishop's Crown and Naranga, therefore making them even less desirable for window growing. Although C. baccatum varieties don't make very good candidates for window growing they still grow very well in a sunny porch or conservatory where they have more space available and better light. Whenever I grow C. baccatum varieties in the greenhouse or outside in the garden I always use a final pot size of 7-litres. Plants belonging to this species are normally very prolific and they set fruit very easily, even when grown indoors in windows. They also grow quite well outside in the UK if you place them in a sheltered spot and provide them with enough support. I'll touch on this a little later.
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| Capsicum Baccatum - Inca Berry (left) and Aji Lemon |
Although Capsicum chinense varieties can be grown in 5-litre pots when space is an issue, they will always grow much better in a final pot size of 10-litres or above. This is because they like to spread out their roots. As is the case with all chilli plants, when grown in smaller pots they will set fruit earlier than plants of the same varieties grown in larger pots. Some C. chinense varieties grow well indoors, even in windows, providing you use the correct pot sizes and provide the plants with adequate light and humidity. However, plants belonging to this species will always perform much better in a greenhouse where they get better light and higher humidity levels. I'll touch a bit more on indoor growing in the next section.
Most Habanero and Scotch Bonnet varieties will grow reasonably well indoors. However, superhot varieties can be much more challenging to grow indoors, especially in windows. Most superhot varieties grow quite tall and don't seem to like the indoor environment very much. You'll have more success growing them in a porch or a conservatory than you will in windows. I've grown Trinidad Moruga Scorpion and Dorset Naga in a southeast-facing window in 5-litre pots, and although both varieties produced fruit they didn't yield anywhere near as much fruit as they do when grown in the porch or the greenhouse. Some of the Capsicum chinense varieties that have performed well for me indoors in windows are Orange Habanero, Aji Mochero, Peruvian White Habanero, Caribbean Red Habanero, Red Habanero, Chocolate Habanero, Mako Akokosrade, Papa Joe's Scotch Bonnet, Aji Charapita and Aribibi Gusano.
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| Capsicum Chinense - Peruvian White Habanero (left) and Orange Habanero |
Capsicum frutescens varieties tend to grow into tall bushy plants and are therefore not very good candidates for indoor growing unless you can provide them with adequate space and light. Although they will grow just fine in a spacious porch or conservatory they won't grow very well in windows due to their growth habits. I've managed to grow a couple of C. frutescens varieties in windows but the yield wasn't great. This is another species that is best suited to being grown in a sunny greenhouse where it can put on its dancing shoes and do the samba.
Capsicum pubescens varieties do not perform very well in 5-litre pots and nor do they perform very well indoors. Although it's possible to get some varieties to set fruit indoors, the fruit is normally smaller and the yield is much lower compared to when they're grown outdoors in a greenhouse or outside in the garden. When growing C. pubescens varieties you should aim for a minimum final pot size of 10-litres. Some smaller fruiting varieties can be grown in 7-litre pots but the yield will be much higher if they're grown in pots of 10-litres or above. I normally grow my C. pubescens varieties outside in the garden in 12-litre pots. Most C. pubescens varieties will grow fine outside in UK gardens providing you anchor down the pots so that they don't get blown over in strong winds and you provide the plants with enough support. However, as already mentioned, when growing plants of this species from seed you should sow your seeds early to ensure that the plants have sufficient time to reach full maturity and produce ripe fruit.
The C. pubescens variety that has always done the best for me indoors is Aji Largo. The growth habit of Aji Largo plants is slightly different to many other C. pubescens varieties in so much as the plants are a little more compact and bushy and the stems are slightly thinner and more pliable. I've grown Aji Largo in a southeast-facing window in both 5-litre and 7-litre pots, and although the plants produced a reasonable amount of peppers the yield was much lower compared to when they are grown outdoors. Capsicum pubescens is definitely an outdoor species. Plants belonging to this species require cooler night time temperatures because it helps with fruit set. Whenever I've grown Aji Largo indoors I've always built a bamboo cage around the plants and then trained the top growth of the plants up two canes that have been fastened to either side of the cage.
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| Capsicum Pubescens - Aji Largo (left) and Mini Rocoto Brown |
Now that you've decided where your chilli plants are going to be grown and what your final pot sizes are going to be, let's get cracking! Before we begin, you're going to need the following items to hand:
- Plant pots
- Potting mixture
- Water
- Bamboo canes
- String or twine
- Cane caps/cane toppers
This next photo shows my Aji Mochero plant 82 days after it broke through the compost and it was now ready for its final pot of the growing season. I chose a final pot size of 5-litres because this plant was to be grown in a southeast-facing window and I didn't want it growing too large. Having grown this variety many times in windows in both 4-litre and 5-litre pots I knew it would perform well in a pot of this size. Aji Mochero is an extremely prolific variety when grown under optimum conditions. If you were to re-pot one of these plants into a 15-litre pot and move it into a greenhouse it would grow into a large bush and produce hundreds of chillies!
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| Aji Mochero - 24th May 2024 |
As already mentioned in the previous section, before removing your plants from their pots you should wet the compost beforehand to help loosen everything up and to make it easier to remove the root balls. The re-potting method that I'm showing below is the same as the one in the previous section. The only difference is here is that the plant pots are larger. I should also mention that when choosing the final pots for your chilli plants you should avoid using pots that are much narrower at the bottom because once your plants have grown to their full size and have started producing fruit they can become top-heavy when grown in these types of pots. If you plan on growing your chilli plants to full maturity in pots like the ones shown in this next photo then at some point you may end up having to use rocks as a counterbalance to stop your pots from toppling over.
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| Avoid Using Plant Pots That Are Much Narrower at the Bottom |
First, you're going to need one of your final pots and an empty pot of the same size and shape as the one your plant is currently growing in.
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| How to Re-Pot Chilli Pepper Plants - Step 1 - Final Pot |
Place a sufficient amount of your potting mixture into the bottom of your final pot so that when the smaller pot is placed into the centre of the larger pot the top of it is level with the top of the larger pot. At this stage, growers using the traditional re-potting method would just remove the plant from its current pot and place the root ball into the centre of the new pot before filling around the edges with potting mixture. This is would be the fastest method to use if you have lots of plants to re-pot at once.
If you're planning to use slow-release fertiliser then this is the stage where you should add it. Sprinkle it evenly over the compost and then cover it with an additional layer of compost before proceeding to the next step. You don't have to cover it with much compost, just enough to ensure that the roots are not in direct contact with the fertiliser granules.
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| How to Re-Pot Chilli Pepper Plants - Step 2 - Final Pot |
Make sure that the smaller pot is central before filling around the edges with potting mixture. You don't want your plants to look like they're growing from the side of the pot instead of in the middle.
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| How to Re-Pot Chilli Pepper Plants - Step 3 - Final Pot |
Next, fill the empty space between the two plant pots with a sufficient amount of your potting mixture, firming it down slightly as you go.
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| How to Re-Pot Chilli Pepper Plants - Step 4 - Final Pot |
When firming down the compost between the two pots you don't need to press down hard, just enough to ensure that it's packed in well and that there are no empty spaces remaining.
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| How to Re-Pot Chilli Pepper Plants - Step 5 - Final Pot |
Once you've finished firming down the compost and when everything looks nice and even you can gently remove the smaller pot from the centre without the potting mixture collapsing in. In the example shown below, I had already removed the smaller pot to empty out the compost that had fallen inside. I then placed the smaller pot back into the central hole just in case I accidentally knocked the larger pot when filling the rest of the plant pots. The photo shown below was taken on the same day that all of my other chilli plants were being re-potted into their final pots using the same method.
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| How to Re-Pot Chilli Pepper Plants - Step 6 - Final Pot |
Before removing your chilli plant from its current pot, gently squeeze around the edges of the pot a few times, and whilst carefully holding onto the plant, turn it upside down and tap and press the bottom of the pot a few times until the root ball drops out. Sometimes, this may take a while. You'll just have to persevere.
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| How to Re-Pot Chilli Pepper Plants - Step 7 - Final Pot |
Once the root ball has been removed, all you need to do is gently drop it into the empty hole and then Bob's your aunty. Congratulations, you've just given your chilli plant some new shoes!
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| How to Re-Pot Chilli Pepper Plants - Step 8 - Final Pot |
After re-potting your plant into its new pot you just need to tidy up the surface of the compost a little. All you need to do is spread one or two small handfuls of potting mixture across the surface until everything looks nice and even. Although you may be thinking that the plant pot looks too full, once you've watered your plants a few times the compost level will sink down slightly. I always fill my plant pots right to the top for this very reason. Also, don't forget to re-insert the plant label!
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| How to Re-Pot Chilli Pepper Plants - Step 9 - Final Pot |
Now that your chilli plants are in their final pots it's time to insert bamboo canes which will be used to provide support for the plants and their fruit bearing branches. Branches that bare lots of fruit can sometimes snap under the weight of the fruit if they're not supported properly. Most chilli varieties will require a cane for support. Although some smaller fruiting varieties that have compact bushy growth habits may not necessarily require a cane, I still recommend using one because it gives you something to tie any branches to later on should you need to do so. It's very disheartening to find a fruit laden branch on the floor of your greenhouse!
If you're planning to grow your plants indoors in windows or in a porch or conservatory, where they won't be subjected to the elements, they're less likely to get snapped than plants grown in a greenhouse or outside in the garden. However, you should still provide your plants with support canes. When growing chilli plants in windows they will grow towards the window pane where the light source is coming from and when doing so they can sometimes become slightly top-heavy, especially if the plant in question produces quite large fruit, such as a Jalapeño plant or Bell Pepper plant. Whether grown indoors or outdoors, chilli plants don't always need their branches tying to a cane, but the plants themselves will nearly always need a cane for extra support.
It helps to know the growth habits of your chosen varieties in order for you to know how long the canes need to be. If you're not sure then I recommend cutting your canes to about 3-feet long. If you discover later in the season that the cane you used for a particular plant isn't going to be long enough then you don't need to remove it to insert another one. You can just extend the length by fastening another cane to the existing one using two or three cable ties (zip ties). When doing this you should make sure there is an overlap of about 12-inches before joining the two canes together with the cable ties.
It's crunch time! Before inserting the bamboo cane, take a look around the plant and find the best spot to insert it. Look for a spot where it will provide good support, but at the same time where it will cause the least obstruction to branches and leaves and to how the plant is growing. You should insert the cane into the growing medium about a finger width away from the main stem. Place your finger between the base of the main stem and the bamboo cane and find the correct spot before inserting it. You only want to insert the cane once, so take your time and find the best spot. You don't want to pull it out and re-insert it multiple times because this will inevitably cause damage to the roots of your plant.
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| How to Re-Pot Chilli Pepper Plants - Step 10 - Final Pot |
Once you've found the best spot, push the cane into the growing medium until it reaches all the way to the bottom of the plant pot. Don't just shove the cane into the growing medium with maximum force or you may cause damage to your plant. Instead, you should insert it using a firm but even amount of pressure, twisting it slightly as you do so. Pushing through the surface is the part that requires the most pressure. Once it has broken through the surface you'll find that it goes through the rest of the root ball much easier. When inserting the cane, place your hand flat on the compost next to the main stem on the opposite side to where you're inserting the cane. This will create a counterbalance and keep the root ball steady as you do so.
As the cane passes through the root ball you'll hear a slight cracking sound, but don't worry because this is inevitable and normal. Once the cane is in place, be careful that you don't knock it or otherwise it may become loose. Obviously, the deeper your plant pots are the more stable your canes will be. Avoid inserting any canes flush with the main stem because you may cause damage to your plants.
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| How to Re-Pot Chilli Pepper Plants - Step 11 - Final Pot |
Once your bamboo cane is firmly in place you can loosely tie the main stem of your plant to the cane using a piece of string or garden twine. Don't fasten it too tightly. Leave some room for the main stem to grow. You can always tighten it up later when your plant has grown larger. Also, it's important that you place a cane cap on the top of all canes to prevent any nasty accidents from happening! I've lost count of how many times I've heard the gruesome story about Mr. Scolland accidentally loosing an eye on a bamboo cane one afternoon whilst bending down to tend to his peas!
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| How to Re-Pot Chilli Pepper Plants - Step 12 - Final Pot |
You can purchase cane caps, also known as cane toppers, quite cheaply on eBay. Incidentally, plastic plant labels and rubber cane caps can be reused over and over again. There's no need to keep buying new ones every year. The triangular cane caps shown in this next photo are over 11 years old. I've written a blog post about reusing plastic plant labels and I've also written one about cleaning garden cane caps at the end of every growing season.
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| Triangular Cane Caps |
Low growing varieties, such as the Aji Mochero plant I'm growing here, may only need tying to the cane with one piece of string because the main stem normally starts branching quite low down. However, taller growing varieties will need tying to the cane with multiple pieces of string in order to support the middle and the top of the plant. You may not necessarily need to do it all at this stage because your plants will still have quite a lot of growing to do, but as they grow taller you should tie them to the cane accordingly. Some varieties that produce quite large fruit, such as Jalapeño, can end up with heavy branches, and if not supported correctly they can become unstable in the pots. Large plants and larger fruiting varieties will definitely need tying to the cane several times.
As always, after re-potting your chilli plants you should give them some water. Although it's not as critical to water them straight away after re-potting as it is after pricking them out and transplanting them, applying water helps to push the potting mixture into place and it also helps to keep the (root) ball rolling. You should wet the entire surface of the compost, making sure that you also apply a decent amount of water at the base of the main stem where the root ball currently is. When watering your chilli plants after re-potting them into their final pots I only recommend watering them from the top for the first few times. Once you see roots starting to poke through the drainage holes you can then start bottom watering your plants if you so desire.
This next photo shows my Aji Mochero plant before being watered-in, and the one below it shows the plant after being watered-in.
.JPG "Aji Mochero - 24th May 2024") |
| Aji Mochero - 24th May 2024 |
.JPG "Aji Mochero - 24th May 2024") |
| Aji Mochero - 24th May 2024 |
By now, you should know where your chilli plants will be living, so all that's left for you to do is place them into their permanent positions for the growing season. If you're planning to grow them indoors you can also juggle them around slightly, but they need to be placed somewhere where they receive at least six to eight hours of sun every day, or in the case of UK chilli growers — they need to be placed somewhere where they could potentially receive at least six to eight hours of sun every day should it ever stop raining.
Most of us have been conditioned to believe that our beloved chilli plants need sun exposure on a daily basis in order for them to yield correctly, but this is not true. Although the sun certainly helps, it doesn't need to be sunny every single day for chilli plants to produce a good amount of fruit. Here in the UK, our weather is unpredictable at best. We may have weeks during the spring and summer where there are no clouds and the sun shines on a daily basis. Then again, we may have weeks where the sun doesn't shine at all because of dense cloud cover. During the summer, we may even have the occasional heatwave where temperatures can soar into the 40s. In such cases, the government will always sound the civil defence sirens just to keep everyone safe! In the UK, we can't guarantee that the summer months will always be hot and sunny. Sometimes, during the summer it doesn't stop raining. As long as you provide your chilli plants with as much light as possible they will normally do just fine.
One thing I've learnt in the years I've been growing chilli plants in the UK is that even during the growing seasons where the weather was very poor the plants still performed well. They just took a few more weeks to produce ripe fruit compared to the growing seasons where the weather was hot and sunny. This is the reason why you should always sow your chilli seeds early if you live in a part of the world that has a cooler climate. Sometimes, we may get into the habit of thinking we can sow our chilli seeds a bit later because when we've done so in the past the plants still reached full maturity in time. The problem with this is that we can't predict what the weather will be like during the growing season. If the summer months end up being a washout you'll wish you'd sown your seeds early, and if they turn out to be hot and sunny you'll end up harvesting ripe chillies a bit sooner than expected.
Growing Chilli Plants to Maturity and Beyond
If you live in the UK or in a country with a similar climate your chilli plants will perform best in a sunny greenhouse, porch or conservatory. If you're fortunate enough to live in a part of the world that is blessed with good weather they will also perform well outside in the garden too. However, as mentioned in the previous section, whether you're growing your chilli plants indoors or outdoors, be it in a greenhouse or outside in the garden, you will need to provide your plants with plenty of support. When growing them outside in the garden it's important that you also anchor the pots to the ground so they don't get blown over in strong winds. Some people just put their plants outside and hope for the best. Don't do that. Not only should they be anchored down, but the plants should also be well supported to ensure that nothing gets broken.
The way I anchor my plant pots to the ground is by first placing a piece of slab under each pot to raise it off the ground by a couple of inches. Using a hammer, I then knock four metal poles into the ground around the pots to hold them in place. Once in place, I then attach the pots to the four poles using some copper wire. Firstly, I fasten a piece of wire around the middle of the pots and then I cut four smaller pieces and attach the wire around the middle of the pots to each of the four poles. This allows me to tighten everything up and make them nice and secure. Not even a gale-force wind would shift them!
My outdoor chilli plants are grown on the lawn, and the reason why I place a piece of slab under the pots is so that I can create a level surface for the pots to sit on. Raising the pots off the ground also allows the water to drain away more freely from the bottom. However, it's important that the slabs are no larger than the diameter of the pots or obviously they will get in the way and stop you from placing the poles flush with the pots. The poles need to be hammered into the ground about a foot deep, and after knocking them in you should also place something on the top of each pole to prevent any nasty accidents.
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| How to Secure Outdoor Chilli Plants to the Ground |
.jpg "How to Secure Outdoor Chilli Plants to the Ground") |
| How to Secure Outdoor Chilli Plants to the Ground |
When growing Rocoto plants outside in the garden I build a cage around each plant using bamboo canes. Some Capsicum pubescens varieties can produce very large, heavy peppers and so it's very important that the plants are supported properly. Building the cages can be time consuming because I have to lash eight lateral canes to four upright canes, but it's worth it in the end. It's nice to have peace of mind on windy days knowing that no matter how windy it gets my plants aren't going to lose any branches due to the weight of the fruit. Some of the Rocoto plants I've grown in the garden over the years have had to endure very strong winds and I've never had any of them get seriously damaged as a result.
Incidentally, when Rocoto plants are exposed to the wind their branches become more pliable, which is no doubt an evolutionary trait due to the environment from where they come from. The cages are mainly built to take the weight of the fruit bearing branches. You shouldn't be too meticulous about tying the branches to the canes because there needs to be room for movement. If branches are tied too tightly to the canes the movement from the wind can cause friction damage to the part of the branch that is in direct contact with the cane. When tying branches to the canes you should do so quite loosely.
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| Homemade Bamboo Cage Supporting Capsicum Pubescens Plant |
When growing chilli plants indoors in windows they will perform best in a south-facing window, but you can also grow them in southeast-facing windows, southwest-facing windows, west-facing windows and to a lesser extent in northwest-facing windows. However, attempting to grow them in north-facing windows is a waste of time because they won't receive enough light. An advantage to growing them in southeast-facing windows is that they also get the morning sun, which is something that chilli plants seem to greatly appreciate.
The sun rises due east and sets due west on the spring and autumn equinoxes. However, during the summer it rises north of east and sets north of west and makes a higher arc across the sky, meaning that plants grown in west-facing windows receive sun in the afternoon and evening, and plants grown in northwest-facing windows receive sun in the late afternoon until sunset. I've grown some chilli varieties in northwest-facing windows, and although they all produced fruit they didn't perform as well as they would have done had they been grown in southeast-facing windows. If you're growing chilli plants indoors in windows and they are a manageable size you can also move them around from one window to another to ensure they get as much sun and light as possible. When growing most chilli varieties in windows in 5-litre pots each plant will need at least 24-inches of space to allow for maximum light penetration and good airflow.
You may have notice by now that I've referred to growing chilli plants in windows and not on windowsills. Let me explain a few things. When growing them in windows they only receive sun and light from the front. Due to the angle of the sun and light coming through the window, placing your chilli plants onto windowsills means that as they grow larger and taller they grow upwards and away from the sun and light angle. When you've just re-potted your plants into their final pots and they're still relatively small it's absolutely fine to place them onto a windowsill temporarily. However, as they start growing larger and taller you will most likely need to place the plant pots below the level of the windowsill in order to catch the correct sun and light angle.
To do this, you're first going to need a crowbar, a lump hammer and a brick bolster chisel to remove the windowsill and a few layers of bricks. I'm joking! Dwarf varieties and some smaller growing varieties can be grown on windowsills providing that your windowsills are deep enough to ensure that your plants aren't growing pushed up against the window pane. However, most windowsills aren't deep enough for most chilli varieties, and varieties that have bushy growth habits will eventually end up growing against the glass, which will reduce the airflow and restrict their growth. Some medium-tall varieties with upright growth habits can be grown on windowsills providing they're only grown in 5-litre pots and that the window is high enough. These types have a different growth habit to most Habanero and Scotch Bonnet varieties. The growth habits of most Habanero and Scotch Bonnet varieties that I've grown made them inappropriate for windowsill growing.
The angle of the sun and light coming through the window needs to hit the front and the top of the plants to ensure they get the most light and to stop them from growing leggy. Depending on the growth habits of the chilli varieties you're growing, to achieve this you may eventually need to position the plant pots below the level of the windowsill in order to catch the correct light angle coming through the window pane. How far down you need to position the pots will just depend on how big your plants are and on the growth habit of each one. You'll just have to keep adjusting the height accordingly. You don't want to place them too low down and nor do you want to place them too high up, which I've already explained. In some cases, you may find that some varieties will grow just fine on the windowsill providing you can move them back from the window pane by a few inches so they're not touching the glass. If you have any cabinets that are the same height as your windowsill then these would be ideal, essentially allowing you to extend the depth of your windowsill.
Attempting to grow a Chocolate Habanero plant or a Papa Joe's Scotch Bonnet plant to full maturity on a windowsill in a 5-litre pot is a waste of time. What you'll end up with by mid-summer is a leggy plant growing up the window pane towards the ceiling with just two or three small chillies on it. Varieties with growth habits such as these can only be successfully grown in windows when you place the plant pots below the level of the windowsill. Depending on how deep your windowsills are, this might mean that your plant pots may be about 8-inches away from the window pane, but at the same time the plants be catching the correct light angle. However, the part of the plant that is above windowsill level will eventually grow towards the window pane, so providing your plants aren't growing a couple of feet away from the windowsill then it's not an issue. When placing the plant pots below the windowsill you need to position them as close to the wall as possible to ensure they are as close to the window pane as possible. The simple diagram shown below will hopefully help to explain it a bit better.
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| Plant Pot Position in Windows |
Wherever you choose to grow your beloved chilli plants, you'll need to provide them with good airflow and as much light as possible. I should also mention that Capsicum chinense is a tropical species and so plants belonging to this species require higher humidity levels than those belonging to the other four domesticated Capsicum species. If you don't provide Capsicum chinense varieties with adequate humidity when growing them indoors you'll end up with excess flower drop. You can raise the humidity level by placing small bowls, shallow jars or ramekins around your plants and then filling them with about a centimetre of water, which you can then keep topping up accordingly. Keeping the water level about a centimetre deep ensures that it warms up faster and evaporates faster. You should use about two receptacles per plant and you should ideally use deionised water because tap water will eventually leave a white crust on the inside, which can sometimes be difficult to remove. However, you should be able to remove it by soaking your receptacles in vinegar for a few hours.
When your chilli plants have started flowering you can also give them a light misting with plain water once or twice each evening, which will also help to raise the humidity level. You don't just need to do this when growing C. chinense varieties indoors; you can also do it when growing them outdoors in the greenhouse too. However, I only recommend misting your plants whilst they're flowering. Once they've set fruit you should stop because it may also increase the chances of mould, especially when growing them indoors or in places with less than adequate airflow, but this has never been a problem for me.
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| Ramekins and Shallow Jars |
As I've already mentioned, when growing chilli plants indoors it's very important to provide them with as much light as possible. I can't state enough how important this is. You can increase the light around your plants by using mirrors and other reflective materials, such as Mylar reflective sheeting. You should line windowsills and the tops of any shelves or cabinets that you're using with a sufficient amount of reflective sheeting to ensure that as much of the surface area as possible is covered. You can also place reflective sheeting behind your plants to reflect light back at them, which is what I always do. You can even use it in your greenhouse to line the floor and the tops of tables or benches. This is especially helpful if you have a tree, fence, shed or hedge obstructing some of the light from entering your greenhouse. I should also mention that white reflects the most light out of any colour.
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| Mylar Reflective Sheeting |
These next two photos show my Aji Mochero plant 30 days after it was re-potted into its final pot and 112 days after it broke through the compost on the 3rd March 2024.
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| Aji Mochero - 23rd June 2024 |
.jpg "Aji Mochero - 23rd June 2024") |
| Aji Mochero - 23rd June 2024 |
The plant had already started flowering and setting fruit, as you can see in these next five photos. By this point, it was well on its way to producing some wonderful spicy goodness!
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| Aji Mochero Flower Bud - 23rd June 2024 |
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| Aji Mochero Flower - 23rd June 2024 |
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| Aji Mochero Flower and Newly Formed Chilli - 23rd June 2024 |
.jpg "Newly Formed Aji Mochero Chillies - 23rd June 2024") |
| Newly Formed Aji Mochero Chillies - 23rd June 2024 |
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| Newly Formed Aji Mochero Chillies - 23rd June 2024 |
When your chilli plants have open flowers on them you can help to pollinate the flowers by giving the plants a light shake every couple of days. This is more important when growing your plants indoors where there is no wind or pollinating insects. You can also do it when growing your plants outdoors in the greenhouse too, but it's not really necessary because the breeze and the pollinating insects, such as bees and hoverflies, will take care of the pollination for you.
Although chilli flowers are self-pollinating, when your plants are grown indoors they still need some help with pollination. You don't need to shake them very hard and nor do you need to lift the plants up in order to do so. All you need to do is hold the top part of the main stem and then give the plants a light shake for a few seconds until you see the leaves moving. This will help to distribute pollen from the stamens (male parts) to the pistil (female parts). When growing your chilli plants indoors you can also point an oscillating fan at them for a few hours each day, and this too will also help with pollination as well as provide good airflow.
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| Pollinating Insects - Bumble Bee (left) and Hoverfly |
In the beginning when your chilli plants have started flowering it's quite normal for them to drop some of their flowers. Not ever flower that your chilli plants produce will develop into a fruit. As I've already mentioned, C. annuum and C. baccatum varieties will set fruit much easier indoors than C. chinense varieties. When your chilli plants have started flowering it's important to maintain the correct moisture level in the potting mixture. You should not over water them but you should also make sure that they don't run out of water. As already mentioned, if you pay close enough attention you'll notice that your chilli plants use more water when they're flowering. If you notice excessive flower drop on your plants it can be caused by too little or too much water, excessively high temperatures, insufficient light, insufficient humidity or too much nitrogen.
When grown indoors, chilli plants tend to drop a few more flowers than they do when grown outdoors in a greenhouse. The indoor environment is not ideal for any chilli plants, it's just that with a few hacks some of them will grow much better indoors than others. As I've already mentioned, Capsicum annuum varieties are the easiest ones to grow indoors, and if you're new to growing chilli plants and you want to grow a couple of plants indoors then you should try varieties such as Ring of Fire, Jalapeño or Malawi Bird's Eye, all of three of which are very easy to grow and will perform very well indoors providing you only use a final pot size of 5-litres.
These next three photos show my Aji Mochero plant 16 days later (128 days after the seedling broke through the compost), and as you can see it was noticeably covered in flowers and some of the chillies were starting to plump up.
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| Aji Mochero - 9th July 2024 |
.jpg "Aji Mochero Chilli - 9th July 2024") |
| Aji Mochero Chilli - 9th July 2024 |
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| Aji Mochero Chilli - 9th July 2024 |
Here it was again 21 days later, and by this point there had been a significant amount of new growth. I knew it wouldn't be long before the first chillies started ripening.
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| Aji Mochero - 30th July 2024 |
.jpg "Aji Mochero Chillies - 30th July 2024") |
| Aji Mochero Chillies - 30th July 2024 |
.jpg "Aji Mochero Chillies - 30th July 2024") |
| Aji Mochero Chillies - 30th July 2024 |
.jpg "Aji Mochero Chillies - 30th July 2024") |
| Aji Mochero Chillies - 30th July 2024 |
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| Aji Mochero Chillies - 30th July 2024 |
If you notice any undersized chillies on your plants then don't be afraid to pick them off. Sometimes, it's not uncommon for some plants to produce small pods in the early stages of fruiting before they start producing pods of the correct size and shape (phenotype). This is especially true for some of the superhot varieties. When growing some superhot varieties (or accessions of them) it's not uncommon for the first chillies to be small, squat and undersized with a smooth exocarp (skin), as opposed to the rough pimply exocarp that most superhot varieties tend to produce. However, it's not just superhot varieties that can produce smaller than normal pods early on. It can also happen with other varieties too, but in my experience it tends to be more of an issue with C. chinense varieties, in particular with some of the Caribbean superhot varieties, such as Trinidad Moruga Scorpion and 7-Pot Brainstrain.
If you notice a few chillies on your plants that appear to have stopped growing and are smaller than the rest then you can just pick them of if you wish. Even if you leave them on the plants they won't grow any larger. Removing small unripe fruits will also encourage the plants to produce more flowers. When you become experienced at growing chilli plants you'll eventually learn to tell the difference between fruits that are actively growing and fruits that have reached their full size. You can tell by the appearance and how soft they are and in some cases by the colour. If you notice any chillies like the one shown in this next photo on your Trinidad Moruga Scorpion plant or 7-Pot Brainstrain plant then just pick them off and add them to your next curry.
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| Undersized Trinidad Moruga Scorpion Chilli with Smooth Exocarp |
These next two photos were taken nine days later, on the 8th August, and as you can see I was only a couple of days away from picking my first ripe Aji Mochero chilli of the season. It was an exciting time and the champagne was on ice in preparation for the big day! 😁
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| Aji Mochero Chillies - 8th August 2024 |
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| Aji Mochero Chilli - 8th August 2024 |
Here was my Aji Mochero plant seven days later, on the 15th August, and as you can see there were a few ripe chillies ready for picking. This variety produces plump, conical-shaped chillies, many of which reach a good size. However, inevitably, as with most varieties, there will always be a few chillies that are smaller than the rest. No matter where I grow this variety, be it in windows, in the porch or outdoors in the greenhouse, it's always the case. This is quite normal. Don't expect every chilli on your plants to be the same size and shape because it's very rarely ever the case. In most cases, there will always be some variation in fruit size and shape.
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| Aji Mochero - 15th August 2024 |
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| Aji Mochero Chilli - 15th August 2024 |
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| Aji Mochero Chillies - 15th August 2024 |
These next five photos were taken on the 7th September and show my Aji Mochero plant 188 days after it emerged from the compost as a small sprout. As you can see, most of the chillies on the plant had ripened and were ready for harvesting. Some had already been picked prior to taking the photos because they were starting to turn soft. I wanted to leave as many on the plant as possible for the sake of taking the photos for this page. If you're wondering why one of the ripe chillies shown below has a piece of red wool tied around its stem it's because that particular fruit had been marked out for seed saving.
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| Aji Mochero - 7th September 2024 |
.jpg "Aji Mochero Chilli - 7th September 2024") |
| Aji Mochero Chilli - 7th September 2024 |
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| Aji Mochero Chilli - 7th September 2024 |
.jpg "Aji Mochero Chillies - 7th September 2024") |
| Aji Mochero Chillies - 7th September 2024 |
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| Aji Mochero Chillies - 7th September 2024 |
In some cases, once your chillies have ripened they are best left on the plant for a few more days because this maximises their flavour. Although they'll still taste good when picked straight away, leaving them on the plant for a few more days allows the terpenes and the true ripe flavour to develop properly. However, most wild chillies are deciduous; meaning that once the fruit has ripened it will fall away from the calyx. This is a trait that wild chillies have because birds are the primary dispersal vectors for wild chilli seeds. Depending on where the plants are grown, if you don't pick wild chilli peppers in time they will either fall on the ground or eaten by frugivorous birds. I once grew a C. chacoense plant in the garden and the birds ate more ripe fruit than I did!
Chillies belonging to the Capsicum chinense species can be left on the plants for a considerable time after ripening before they start to turn soft. Capsicum pubescens varieties benefit greatly from being left on the plants after ripening because it allows their juiciness and ripe flavour to develop properly. Although they may look ripe, if you leave Rocoto peppers on the plant for another week or so you'll notice that they eventually turn a darker colour, and this is when they're at their best. Capsicum annuum varieties shouldn't be left on the plants for too long after ripening because they start turning soft much faster. Thicker-walled varieties, such as Bell Pepper and Jalapeño, can be left on the plants for quite a while, but thinner-walled varieties, such as Ring of Fire and Bangalore Torpedo, will start turning soft very quickly and should therefore be picked after a couple of days.
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| Aji Mochero Chilli Harvest - 7th September 2024 |
When harvesting ripe chillies you can either carefully pick them from the plant or you can cut the stem with a sharp scissors. There is a correct way to remove chillies from the plants, but in some cases it may be better and easier to just remove them using a scissors. Some varieties are more delicate than others and the fruit on some varieties may be more stubbornly attached to the plant and if you pull too hard you could easily damage the plant. Until you get the knack of removing them by hand you can just remove them using a scissors instead.
The Aji Mochero plant shown on this page was started from seed on the 24th February and it took nine days to germinate. It was pricked-out and transplanted on the 10th March and the seedling was raised under a homemade grow light until being re-potted into its second pot on the 13th April. It was then moved into a porch on a permanent basis until being re-potted into its final pot on the 24th May, after which time it was then moved into a southeast-facing window where it spend the remainder of the growing season.
An indoor chilli plant grown in a small pot in a window isn't exactly the best plant example to use when putting together a webpage on how to grow chilli plants. However, by the time I'd decided I was going to put this page together in early 2024 it was the only growing space I had left. Hopefully, there was something of value on this page for you, even if it was just to see an example of what can be achieved if all you have available is a sunny window to grow a few small chilli plants. Most of my chilli plants are grown in either 5-litre or 7-litre pots, and at the end of every growing season I harvest enough ripe chillies to fill three freezer draws. That's enough chillies to keep me going for a whole year!
.jpg "Chilli Harvest - 29th October 2024") |
| Chilli Harvest - 29th October 2024 |
If you want to purchase chilli seeds then a list of my recommended chilli seed sellers can be found on the links page. New links are added to the page occasionally and I only list websites that I use or have used myself. If you fancy making a homemade salsa, hearty bowl of chili con carne or spicy Indian curry then I also have a recipe page that may be of interest to you. New recipes are added to the page occasionally, but because this website isn't about cooking I don't add new ones very often. If you get confused about any of the ingredients listed in some of the recipes then I've also written a page on herbs and spices to help you out. Finally, if you're looking for information on how to preserve your home grown chilli harvest then I've written a page on that too.
Bon appetite and happy chilli growing! 😈