Peppers, including sweet varieties and chillies, are tender crops that repay warmth and patience with colourful fruit. They thrive best in a greenhouse or polytunnel, although a very sheltered, sunny patio can work in warmer southern gardens.

When and how to sow

Sow in module trays of seed compost under cover from February to March, keeping seedlings warm and well lit. Pot on individually once roots fill their cells. Plant into greenhouse borders, large containers or a warm outdoor position from late May, or June in cooler districts, only when frost risk has passed. Space plants about 45 cm apart in moisture-retentive, free-draining soil.

Care

Water regularly so compost never swings between sodden and dry, especially once fruit is forming. Support taller plants with canes and soft ties. Feed weekly with a suitable liquid fertiliser after the first fruits set, and ventilate a greenhouse on hot days.

Common problems

Aphids can distort young shoots, while greenhouse whitefly may gather beneath leaves. Inspect plants frequently, remove heavily infested growth and encourage ventilation. Cold nights, poor light or erratic watering can delay fruiting and cause blossom drop, particularly in exposed outdoor sites.

Harvest

Pick chillies or sweet peppers with secateurs once they reach their expected size and colour. Green fruit can be harvested earlier, but allowing peppers to ripen red, yellow or orange usually improves flavour. Regular picking encourages further flowers and fruit.

Growing Peppers: frequently asked questions

When should I sow peppers in the UK?

Sow in module trays of seed compost under cover from February to March, keeping seedlings warm and well lit.

What are common problems when growing peppers?

Aphids can distort young shoots, while greenhouse whitefly may gather beneath leaves.

When is peppers ready to harvest?

Pick chillies or sweet peppers with secateurs once they reach their expected size and colour.

General guidance for UK home gardens and allotments. Reference figures are typical values; your exact timing depends on your region, last-frost date and variety. Page updated 19 Sep 2026.