How to grow chillies and peppers

Chilli peppers and sweet peppers are members of the capsicum family. Chilli peppers (usually referred to as chillies) are grown primarily for their hot spiciness and are mainly used in cooking whereas sweet peppers (or just peppers) are grown for their sweet flavour and are equally useful in cooking or eaten raw in salads.

Chillies and peppers are often sold in shops as green, yellow, orange and red but most chillies and peppers will all eventually ripen to red and the colour is just a matter of how ripe the fruit is when picked. Chillies become hotter as they ripen and peppers get sweeter. The benefit of harvesting unripe fruits is that it will keep your plants productive longer but for their best heat and flavour they need to ripen fully.

Chillies originated in Mexico so whilst they are not difficult to grow you do need to be aware that they need warm temperatures to thrive, especially when small.

Sow chilli and pepper seeds

Chilli seeds and pepper seeds can be sown from February until April, sowing early will give you an earlier crop. I sow in small cells with just one or two seed per cell, this makes potting on easier. Ideally, place in a heated propagator as a temperature of about 21 Celsius is required for germination. If you don’t have a propagator sow in small pots, cover with a plastic bag and keep in a warm, sunny window sill.

When the seeds have germinated remove them from the propagator and place on a warm sunny window sill, remove the plastic bag if using that method. Leaving them for too long in the propagator will make your plants weak and leggy.

When the seedlings are big enough to handle prick out and transplant to a 5 cm pot and keep in the same sunny, warm conditions.

Grow chillies and peppers

When your chilli plants and pepper plants have outgrown their pots move to a 15 cm pot and move to the greenhouse if the weather is good enough. Finally move to 20 cm pots or grow bags in the greenhouse.

It is possible (I’m told!) to grow chillies and peppers outside against a south-facing wall if you’re fortunate enough to have one, which I don’t. Last season I had more plants than I had room for in my greenhouse so I planted them in a sunny spot in the garden. To be fair, they didn’t get as much attention as the greenhouse ones but they only grew to about 15 cms tall and didn’t have a single flower. The greenhouse ones were very good.

Support your plants with canes as they grow.

Pinch out the growing tip when the plants are about 30 cms tall and the plants will become more bushy and bear more fruit.

Keep watered and feed once a week with a tomato feed diluted to the pack instructions.

Harvest chillies and peppers

Chillies should be ready to harvest from July until September or October. Harvest chillies as you require them or when they turn red. Regular harvesting will produce more fruit. Sweet peppers are best left to ripen completely. Though I often find the season is not long enough for this to happen. Although not so sweet they are perfectly edible.

Chilli and pepper problems

Greenfly is a sap-sucking aphid that is a common problem. Serious infestations weaken the plants and reduce yield. Greenfly multiply rapidly so keep an eye open for them and act promptly. Squeeze between finger and thumb to eradicate them, spray with soapy water if this is not effective. Other organic sprays are available.

Whitefly are a tiny fly that also weakens the plant by sucking sap. They can be caught on sticky fly strips. Organic products are available to treat both whitefly and aphids.

Botrytis or grey mould is a fungus which affects damaged areas and causes a grey fuzzy mould to appear. Prevent infection but removing any dead or damaged parts of your plants. Remove dead leaves and debris from the greenhouse and keep humidity low by ventilating well.