Bell pepper

Light and exposure

The bell pepper demands full sun and warmth, plenty of warmth. Give it the most sheltered and brightest spot you have: a greenhouse, a tunnel, a conservatory, or failing that the foot of a south-facing wall that releases heat at night. Below six hours of direct sun a day, the plant lingers and the fruits struggle to ripen.

Under our skies, shelter makes all the difference. Out in the open vegetable garden, a bell pepper survives but stays stunted and cropping comes late; the same plant in a greenhouse starts two to three weeks earlier and completes its season. If you have no greenhouse, save the warmest corner for it, against a light-coloured facade, sheltered from the wind.

Watering

The bell pepper wants a soil that stays cool and steady, without sudden swings. Water at the base, never on the foliage, preferably in the morning. It is precisely irregular watering that causes blossom end rot, that fruit bottom which blackens and rots, linked to poor calcium transport when the plant goes thirsty then drinks all at once.

In a pot or greenhouse, the growing medium dries fast in full heat and may need water every day in July and August. A mulch at the base keeps moisture steady and limits the swings. Reduce watering at the end of the season, when the fruits are finishing reddening and the plant slows down.

Soil and repotting

The bell pepper likes rich, deep, well-drained soil. Work the ground with mature compost or well-rotted manure before planting; it is a hungry feeder and produces for a long time. Heavy, cold soil makes it sulk; if the soil is clayey, lighten it and raise the bed to warm it up.

Never plant out before mid-May, once the ice saints have passed and the ground has warmed. Space the plants 40 to 50 centimetres apart. In a pot, allow at least 10 litres per plant, with good drainage at the bottom; in a greenhouse, open ground remains ideal to sustain a long fruiting period.

Temperature and humidity

This is the critical point for us. The bell pepper grows well between 20 and 28 degrees and stops dead below 12 degrees: the flowers drop, growth stalls. It tolerates no frost, and a single cold night is enough to set a young plant back for several days.

At sowing, it needs warmth: 22 to 25 degrees to germinate, with supplementary light in February and March or the plants grow leggy. Do not trust a mild April; late frosts return until mid-May. In a greenhouse, watch out too for excess heat in high summer and ventilate, because above 35 degrees the flowers also abort.

Pruning and upkeep

The bell pepper does not need heavy pruning, but a few gestures help. Many gardeners pinch out the first flower, the one at the central fork, so the plant branches out and yields more afterwards. Stake well-laden plants: the branches are brittle and the weight of the fruit easily flattens them.

During the season, remove yellowed leaves and the low suckers that touch the ground. In a greenhouse, training on two or three main branches, tied in, gives airy, healthy plants. Harvest with secateurs; the stem is woody and snapping off a fruit by hand damages the branch.

Pests and diseases

Under our humid summers, blossom end rot is the most common trouble: the bottom of the fruit blackens and caves in. It is not a disease but a calcium deficiency linked to swings in watering; steadily moist, mulched soil prevents it. Grey mould, botrytis, sets in on tissue damaged by mild, stuffy weather, especially in a poorly ventilated greenhouse.

Among pests, aphids colonise the young shoots in spring and transmit viruses; hose them off and encourage ladybirds. In a greenhouse, red spider mite thrives in dry, hot weather and stipples the foliage with yellow dots: mist the paths to raise the humidity. Watch out too for slugs on young plants just set out.

Propagation

The bell pepper is propagated by sowing, and you must start early. Sow from February or March indoors, in warmth between 22 and 25 degrees, in a fine compost, barely covering the seeds. Germination takes one to three weeks depending on the warmth; without supplementary light at this time of year, the seedlings grow leggy, so place them as close as possible to a bright window or under a lamp.

Prick out into individual pots as soon as there are two true leaves, and keep the young plants nice and warm until they go out. Taking cuttings has no practical value here: with a frost-tender annual, you start afresh from seed each year. You can save the seeds from a fine, fully ripe red fruit, provided it is not an F1 hybrid.

Month-by-month care calendar

Green Hub tips

• Sow from February or March in the warmth with light. Without this head start, you will only have a few green peppers before autumn.
• Grow under a greenhouse or tunnel if you can. In the Belgian open air, the harvest stays late and red is almost impossible to obtain.
• Water at the base, regularly, without swings. It is the best defence against blossom end rot, that bottom rot linked to a lack of calcium.
• No greenhouse? Set the plants against the warmest wall, due south, and mulch to keep the soil cool and steady.