How do I grow chillies and peppers?

Chillies and peppers are tropical plants with a long growing season, which is the main constraint in a temperate climate. Everything about growing them is about maximising warmth and starting early enough for the fruit to ripen.

What you'll need

• Seed
• Warm propagation space
• Pots and compost
• Greenhouse or sunny windowsill (optional)
• Tomato feed (optional)

Step by step

1. Sow early, well before the last frost.They need a long season. Eight to ten weeks before the last frost is a minimum, and hotter varieties need longer still.
2. Germinate them warm.Around 20-25°C. A heated propagator or an airing cupboard makes a substantial difference; they germinate poorly and slowly in a cool room.
3. Give maximum light as soon as they emerge.The brightest windowsill or a greenhouse. Leggy stretched seedlings never make good plants.
4. Pot on as they grow rather than starting in a large pot.Successive pots keep the roots active. A seedling in a large pot sits in cold wet compost.
5. Grow under cover in cooler climates.A greenhouse, conservatory or sunny windowsill. Outdoors in a cool summer, many varieties will not ripen at all.
6. Feed with a high-potassium tomato feed once flowering.Nitrogen before that for growth, then potassium for fruit. Continuing with high-nitrogen feed gives a large plant and few chillies.
7. Water consistently but do not waterlog.Erratic watering causes flower drop and bitter fruit. They dislike sitting wet, so free-draining compost matters.
8. Pick regularly to keep it producing.Green fruit picked keeps the plant flowering. Letting everything ripen on the plant slows production considerably.

Tips

• Chillies get hotter with stress — slightly less water and more sun produces hotter fruit than a pampered plant.
• Plants can be overwintered indoors somewhere frost-free and cut back hard. A second-year plant crops much earlier.
• Hand-pollinate with a soft brush if growing indoors, where there are no insects to do it.

Common mistakes

• Sowing too late — They need a long season and the fruit will not ripen. Late sowings give plants that flower as the season ends.
• Continuing with a high-nitrogen feed — It produces lush foliage and very little fruit. Switch to a high-potassium feed once flowers appear.
• Growing them in a cool shaded spot — They are tropical plants. Insufficient warmth and light gives few flowers and unripened fruit.

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