Updated: Jan 19
I’m not entirely sure when my joy for growing chillies began but I distinctly remember when it started getting a little out of control. I’ve always enjoyed cooking with chillies and when I was living in a small flat, I really missed growing vegetables and so I decided to give chillies a try. They grew fantastically and it wasn’t long before I worked out that with four window ledges (North-West facing) I could potentially grow in total twenty chilli plants, fitting five plants comfortably on each window ledge. With a certain lack of willpower I actually ended up growing far more than I needed or had room for, so these were given new homes with family and friends. Over the course of three years I grew close to seventy different varieties, varying colours, sizes and heat.
But it didn’t stop at just growing chillies, I read about them, I researched them, I visited chilli farms, went on chilli ‘experience’ days and even attended the West Dean Annual Chilli Fiesta which is the UK’s largest chilli festival, with live music and celebrating all things chilli...they even have a mariachi band! Sombrero’s are optional but if you don’t wear one you are seriously missing out. The best part is that West Dean have these glorious Victorian Glasshouses full to the brim with over a 100 different varieties, it’s one of the most beautiful displays I have ever seen in a stunning setting. If you haven’t been definitely put it on your to bucket list.
So back to growing. The first thing I was taught about growing anything successfully, is to know your plant, find out where it originates from and what its natural habitat is. Those are the conditions you try to achieve in order to help it to thrive. Getting the right environmental conditions is vital. In the wild chillies grow as perennial shrubs, their natural range extends from the southern region of Northern America (Mexico), to the temperate regions of South America. So the key thing that tells us is that they like warmth and light. Similar to aubergines and tomatoes, chillies do well grown in a greenhouse or polytunnel (or in my case a warm bright window ledge).
Sowing Time - the hottest varieties are slow growing and require a long season, so it’s best to get started on these early. January is a good time to start sowing seeds indoor or in a heated propagator.
Temperature - chillies don’t actually require light to germinate, they just need heat. If you don’t have a heated propagator or greenhouse, I’ve found putting trays in an airing cupboard works great too. I’ve even heard of serious growers warming the compost to around 20-30 degrees celsius to aid germination but I’ve never actually had to try that method.
Growing Medium - a seed sowing compost is recommended by most growers as it’s a little thinner than regular compost but I prefer to use coir. Coir is lighter and more free draining than regular compost and I find that it works better. The growing medium needs to be moist but not wet and sow seeds to a depth of 2-5mm and generous spacing in between or if you are sowing in module cells, 1-2 per cell. You can always thin out the weaker of the two. Cover lightly with vermiculite (or more growing medium if you don’t have any vermiculite). Take care not to let the growing medium dry out.
Light - after 7-14 days (some varieties may take a little longer) you should have germination at which point, if you have used the airing cupboard trick move them into a warm spot with natural light.
Pricking Out & Potting On
Like all seedlings wait until the chillies have produced their true set of leaves before transplanting into individual pots. You can refer to my previous blog How to Sow & Grow for more step by step instructions, however the key thing to remember for chillies is heat, so once potted on they need to stay around 18-20 degrees celsius for good growth. Feeding the plant with a high nitrogen feed in the early stages helps to encourage green growth, switch to high potassium once well established to encourage flowering.
For taller varieties like Capsicum annum it is recommended that once your plant reaches about 30cm in height, pinch out the growing tip to promote branching and bushier growth but otherwise you don’t need to prune through the season. I recommend pinching out side shoots when the plant is young so that all the energy goes into producing flowers and therefore fruit.
Keep the plants around 25 degrees celsius to promote fruit-setting. If the plants are exposed to temperatures lower than 17 degrees celsius they can experience blossom-drop which as the name implies is where the flower drops from the plant and therefore fruit cannot be produced. This can also happen if the flowers have failed to be pollinated. You can make sure they have been pollinated by lightly rubbing the inside of each flower with a little paintbrush. Feeding plants will also help fruits develop, making sure it’s a high potassium feed like, tomato feed, seaweed fertiliser or homemade comfrey feed will do nicely. I have seen a professional chilli grower remove the first flush of small flower buds to help increase further flower production.
Chillies are very forgiving and will recover from periods of draught to some extent and it’s recommended to allow the plant to completely dry out between watering, this will help with the temperature of the chillies, making them hotter in flavour. However this is at the detriment to your overall yield which may be smaller as the plant will be weakened, so I guess it depends how hot you like them. However, I find watering them thoroughly in the mornings keeps them ticking over nicely and if its particularly hot, water again in the evening. They are very quick to tell you when they are unhappy and become very flaccid in form. I’ve found watering very much depends on temperature and where you are growing them. When I was growing all my chilli plants on a North-West facing window ledge they rarely required water twice a day but now I’m growing them in a greenhouse, different watering schedule. My advice would be when you water, water throughly.
Chillies can be picked at any stage and most people don’t realise but when chillies are in their initial green stage, they are at their hottest in flavour. And picking the first few whilst still green, encourages the plant to produce more (these will still ripen, off the plant in a warm environment). If you pick when the chillies are red (or any of other glorious colours they ripen to) this will make them milder in taste with the chilli having reached its full ripened stage.
Since they are a perennial most chillies can be overwintered as a house plant but would require pruning in the winter, some of the small varieties are perfect for this. However, in the UK we tend to treat them as an annual - just don’t forget to save some seed of your favourite for re-sowing next season.
The biggest problem for chilli growers is aphids, without a doubt every year I get aphids (even when I was growing in a flat on a window ledge!) However last season I used a recommended homemade organic spray which appeared to have an impact on the aphid population - take tomato leaves, soak them in a bucket and leave overnight (similar process to making comfrey feed) and drain the liquid into a spray bottle and spray the plants thoroughly. Avoid spraying them mid-day as it could cause leaf scorch and be warned it comes with an odour. This season I’m also going to be adding the additional of lemongrass to the greenhouse, as a recommendation from a professional chilli farmer, apparently they are deterred by the smell. They can and do suffer from whitelfly, red spider mite, mealybug and capsid bugs. In all of these cases I would simply try to encourage predators into the garden, like ladybirds and other predatory mites which are all available to purchase if you are struggling to create a natural eco-system within the garden and you need a quick fix.
Non bug related problems are;
Yellowing leaves this is generally a nutrient deficiency, so give them plenty of feed
Flower drop as previously discussed this is reasonably common and due to temperature drop or lack of pollination, so try where you can to give them a consistent environment to grow in and if growing indoors you may have to give the pollinators a help with the paintbrush
Leaf drop if lower leaves are dropping off this could mean you are overwatering, so hold back and allow the compost to dry out between watering. If the top leaves start to fall this is temperature related, so keep them cosy
Corking this is when fine lines appear on the fruits, like little scars, this is very common in Jalapeños and is caused by a sudden growth spurt, nothing to worry about, they are still edible and won’t taste any different
Small, misshapen or seedless fruit this is due to poor pollination but again perfectly edible, just make sure you help the pollinators with your paint brush
Blossom end rot more prevalent on tomatoes but also happens with larger fleshier chillies, which is caused by a calcium deficiency and this is due to irregular watering which prevents the flow of calcium through the plant, to avoid this try to water regularly and evenly
A chilli’s heat is measured by a Scoville scale, created in 1912 by an American chemist Wilbur Scoville. Wilbur devised a test for measuring the heat of chillies by diluting the chilli concentrate in sugar syrup and with the aid of human tasters, the solution would be sipped to see if they could taste the chilli. The more the chilli concentrate needed to be diluted, so the taster could no longer detect the chilli flavour, the higher the Scoville rate. This is shown on your seed packets as SHU Scoville Heat Units.
although treated in culinary terms as a vegetable or spice, they in fact a berry/fruit of the plant
since their discovery they have made their way across the entire globe to Spain, South Africa, India, Indonesia, Japan, China and finally making there way to Europe
stressing the plants by denying them food & water and subjecting them to extreme heat for periods of time can cause the plant’s natural defences to kick in and make the fruits spicier in a bid to stop them from being eaten by predators - but be careful not to kill the plant entirely on your quest for a really hot chilli
a general rule is the smaller the chilli the hotter it is but I’ve found this is not always the case, especially with all the cultivation that’s happening
there are 10,000 varieties to choose from
the very hottest varieties are actually the slower growers
capsaicin is the compound within the chilli that produces the burning sensation, however it isn’t what actually burns you, it just triggers the burn receptors in our brain which causes the running nose, sweating and watery eyes
the hottest part of the chilli is the placenta, which is the white pithy strip that holds the seeds to the pod
Here are some of my favourite chilli people and what they don’t know about chillies, isn’t worth knowing, take a look and be inspired;
South Devon Chilli Farm
Dartmoor Chilli Farm
Upton Cheyney Chilli Farm
West Dean Gardens
So get sowing your seeds now and I will write another blog later in the season to discuss all the fantastic things you can do with your yield.