Golightly Gardens: How to grow sweet peppers and chillies

Here is a guide to everything I know about growing sweet peppers and chillies. It hasn’t been a good year for growing sun-loving plants, but we managed a pretty respectable and flavoursome crop against the odds, so you might like to get the benefit of the most recent experiments.

At Golightly Gardens we grow our own food for two reasons: firstly, to save money, and secondly, for flavour and freshness. Pepper plants aren’t easy to grow in a cost-effective way, so if you can’t get a good yield then it’s better value to buy your peppers and chillies from a greengrocer or a supermarket, or pick up a mid-priced hothoused patio plant from a garden centre that looks vigorous and already has plenty of fruits on it.

Still want to grow some yourself? Okay, on with everything…

Sweet peppers and chillies are not suited to the British climate. This is probably the single most important thing to remember. These plants need cosseting and ideal conditions otherwise they are not really worth growing. They need lots of sunlight, warmth, and shelter from the wind. Their ideal home is a heated greenhouse – but this isn’t cost-effective, of course, so the next best spot is a bright windowsill. You can also get some good results with an unheated greenhouse or polytunnel. The next best option is a baking hot, sunny, sheltered patio, but if the temperature falls much below 10 degrees C then don’t expect much.

They need a long, long growing season. Start germinating your pepper seeds in January, or February at the latest. I don’t use a heated propagator or anything fancy at all, just a plastic takeaway container on a sunny windowsill filled with a mix of sharp sand and compost, with cling film over the top. Classy. Be aware that some varieties can take up to a month to germinate, 21 days is certainly not unusual. Prick the seedlings out when they have two true leaves, and pot them on. The seedlings aren’t particularly delicate, which is a bonus. It’s also a good idea to look for seed varieties that are ‘early’ or ‘extra early’, the ones that produce fruit sooner in the season.

F1 plants tend to be the best producers, especially for sweet peppers. This is where it can get expensive. F1 seeds are hybrids and cross-breeds which give you the best qualities of different types of sweet pepper and chilli, so they’re viable for growing in the British climate. Generally speaking, because they are cross-breeds you can’t keep seeds from the fruits at the end of the growing season, because the next generation will not remain true to type. This means you have to keep going back to the commercial seed producers for more, which raises your cost of growing. As you’re likely to be growing on a windowsill, you could end up with far more seeds than you need. One possibility is to buy just one F1 variety, and swap a few spare seeds with friends and neighbours to get more variety for your money.

There are a few ‘open pollinated’ types which grow well and allow you to save seed for the next year though – look out for ‘Gourmet’ variety sweet peppers (blocky, turn from green to orange, RHS Award of Garden Merit for flavour), and cayenne (medium-hot multipurpose chilli) and Hungarian hot wax chillies (very mild, large).

Chillies like to be a little cramped. You can grow up to three plants in a nine inch pot and they will be quite happy. Sweet peppers like a little more room, but I’ve done well with most of mine in six inch pots this year. You don’t need to buy masses of compost, or use up precious home made compost anyway.

Water them little and often. They prefer a small amount of water in the morning, and need fairly good drainage. Irregular watering can cause the plants to drop their flowers or fruit. Try not to leave them standing in a waterlogged pot or in a pool of water, especially overnight, as they really don’t like it.

Sweet peppers and chilli plants like slightly acidic soil. Buying specialist ericaceous compost is far too pricey. I make soil in pots a little more acidic by mulching with used tea leaves half way through the growing season, and occasionally watering with leftover, diluted cold black tea or coffee. That’s a free way to do it. You could also lightly water once every few weeks with a white spirit vinegar solution (15ml in one pint of water), which only costs a few pence.

Their main pests can kill the plants very quickly. Sweet pepper plants and chilli pepper plants can be decimated by nasties like spider mites and aphids (mostly greenfly). These pests can double in number in around 5 days – aphids are born pregnant – and if you spot them, they need to be treated/removed ideally on the same day. Commercial treatments are expensive and may cause problems if you’re trying to grow organically. I’ve also found that the usual home made treatment of a few drops of organic washing up liquid in water tends to ‘burn’ the leaves on the plants, however dilute you make it.

For the cost-effective organic gardener, the best option is probably to squish as many bugs as you can by hand, then blast the rest off with a jet of water. If there are spider mites, and the infestation is so bad that you can see their ‘webs’ with the naked eye, your plant is probably not going to make it – remove the most badly infested plants and ideally burn them so they cannot infect other plants.

Chilli plants and sweet peppers like to be misted. A misting of warm water from a cheapo water sprayer with an adjustable nozzle can work wonders. It helps the flowers to ‘set’ i.e. get pollinated and start making fruits, and it also discourages those evil little spider mites from taking over your plants.

Kill the king. Chilli plants sometimes start to grow one huge, single chilli at the spot where the main branches leave the stem. If that happens, the plant will put all its effort and energy into growing just the one chilli and won’t make any more flowers or fruit. The simple solution is to cut this chilli off the plant while it’s still green. The good news is that it’ll be edible, so add it to your cooking. Le roi est mort, vive le roi and all that.

Bushy is probably better. Many sweet pepper and chilli plants grow tall and spindly, and don’t make much fruit. If you’re feeling brave, you can make a plant grow bushier by pinching out the growing point at the top when the plant is about 25cm tall. It will then send out other branches. If you decide to do this, remember to provide extra support for these branches, as they can in theory become weighed down with fruits.

A little tomato food makes sweet peppers and chilli plants happy. Once the flowers have started to set, all you need to do is water every week or two with half-strength tomato food to get a higher yield. A little goes a long way, and I’ve found that even the cheapest tomato food, eg Poundland’s, makes a fair difference.

You could get a second crop of chillies for Christmas. I’m not sure this works with sweet peppers (although I’ll be trying to find out in the next couple of weeks), but I have found that if you bring chill plants indoors from the garden just before the first frosts, they tend to re-flower and give you a whole new set of chillies once they’re warmer and happier. Last year we had a stack of lovely second-wave cayenne peppers that went until the end of December.

Chilli peppers and sweet peppers are easy to preserve. You can do all sorts in the moderately unlikely event of ending up with a glut. Sweet peppers are best if you roast or grill (and peel) before freezing them. They’re also nice cooked into stews and ratatouille and then frozen, or cooked in a red pepper sauce. The sauce can be bottled and sterilised, or simply chucked in the freezer in a freezer bag.

Chillies can be strung up and dried in an airy spot, or pickled, or used to flavour cooking oil. If you’re using them to flavour oil, you can use them fresh then strain out and discard them, or dry them thoroughly then place in the oil and leave them there. Some people say they freeze whole chillies but I haven’t tried this yet, so am not really sure about that one.

There you go – I’m sure there will be more tips next year, when I try out new varieties and growing techniques. Do you have any tips of your own?