For the best and hottest chillies, start sowing indoors as early as January (although if there are late frosts, you can in some years get away with sowing in March) – the hottest varieties often need the longest growing period. Chillies need plenty of warmth to germinate so invest in a heated propagator for the windowsill or use a warm airing cupboard.
Sow Chilli pepper seeds on the surface of a moist, free-draining, seed compost and cover with a fine sprinkling of compost or vermiculite. Place seed trays in a propagator at a temperature of 18-25C (64-77F). If you don’t have a propagator, use polythene to cover your seed trays.
Germination usually takes 7-10 days, after which you can move your seedlings to a warm, sunny windowsill or a heated greenhouse. Keep the compost evenly moist but take care not to let it get soaking wet.
When your chilli seedlings are big enough to handle without breaking, transplant them into individual 7.5cm (3″) pots of compost and grow them on until all risk of frost has passed, and they are large enough to be transplanted to their final positions. From an early sowing, this will normally be from May onwards.
Grow chillies individually, transplanting them into 2 litre containers, or plant them in grow bags allowing three plants per bag. Place pots or growbags under cover in a warm greenhouse, conservatory, or polytunnel.
Alternatively, plant your chillies outside in a sunny, sheltered spot. Gradually acclimatise your plants to outdoor conditions over a period of 7 to 10 days before transplanting them into well prepared beds of fertile, moist, well-drained soil. Space chilli pepper plants 50cm (20″) apart. Short of space? Try growing them indoors on a sunny windowsill.
Water chilli pepper plants regularly throughout the growing season, and once the first fruits have set, feed them weekly with a high potash tomato fertiliser. Also remember to:
• Pinch out the growing tip of the first flowering shoots to promote more branching and a better harvest.
• Water regularly but sparingly. It’s best to keep your soil a little on the dry side because slightly stressing your chilli plants helps to produce hotter peppers. Taller varieties of chilli pepper may require staking.
• Add a thick mulch of organic matter around the base of the plants to help conserve moisture and suppress weed growth.
Growing chillies indoors? Do remember to open windows and doors to provide insects access to the flowers to ensure good pollination. Alternatively, hand pollinate the chillies by moving from flower to flower, tickling the centre of each with a fine artist’s paint brush.
Chillies require warmth and long sunny days to ripen properly. From an early sowing, this shouldn’t be a problem, but later sowings in the UK may leave your peppers feeling the cold as summer days begin to shorten.
If your crop has yet to ripen, bring your plants indoors and let them ripen on a warm sunny windowsill. Harvest chillies singly by cutting them from the plant with secateurs. Chilli peppers grown outdoors must be harvested before the first frost.