Can I grow sweet peppers outdoors in the UK?

Marginally and only in southern England in a sheltered south-facing position, ideally in pots that hold heat. Even there, outdoor yields are 30–50% of greenhouse yields. North of the Midlands, outdoor sweet peppers rarely ripen fully — grow under cover instead. The plants need consistent warmth above 15°C and protection from wind.

When should I sow sweet pepper seeds?

Late February to mid-March in a heated propagator. Earlier sowings (January) lead to leggy plants by planting-out time; later (April) leaves too little growing season. Sweet peppers need 18–22 weeks from sowing to first ripe fruit, so an early start is essential in our short summer.

Why are my peppers tiny and not setting?

Cold weather. Peppers stop flowering and fail to set fruit below 15°C — common in early UK summer. Move plants to a warmer position, keep them sheltered from cold nights, and be patient. Once temperatures climb consistently above 18°C through July, set rates improve dramatically.

What's the best variety for the UK?

For greenhouse / polytunnel: Bell Boy (classic blocky), Marconi (Italian pointed), Sweet Banana (long mild, very prolific). For containers and small spaces: Redskin and Mohawk are compact F1s that crop heavily. Avoid heritage open-pollinated cultivars — they need warmer summers than the UK provides.

When can I pick sweet peppers?

Green peppers are pickable from late July onwards once they reach full size. For coloured (red, yellow, orange) peppers, leave them on the plant another 2–3 weeks after reaching full size — they turn colour and sweeten dramatically. The last fruit can be picked into October from greenhouse crops.

How do I store sweet peppers?

Refrigerated, 1–2 weeks in the salad drawer. Sliced and frozen on trays then bagged — keeps 6 months; texture softens but flavour holds for cooking. Roasted, peeled and preserved in olive oil — classic Mediterranean approach for a glut.

Sweet pepper / bell pepper

Capsicum annuum

vegetable☀️ full_sun🪴 loamy📏 medium🌡️ RHS H1c

📋Quick Facts

Height

0.6-0.9m

Spread

0.4-0.5m

About

Sow sweet pepper seed indoors from late February to mid-March in a heated propagator; the long UK season makes an early start essential. Peppers are frost-tender (RHS H1c) and want consistent warmth above 15°C to flower and fruit, which in practice means a greenhouse, polytunnel, conservatory or warm windowsill — outdoor crops in pots are possible in sheltered south-facing positions from June to September but rarely match indoor yields. F1 hybrids like Bell Boy, Redskin (compact) and Sweet Banana suit UK conditions. Pinch out the growing tip at 30 cm to encourage branching. Pick green or wait for full colour (red, yellow or orange) — colour develops over the last 2–3 weeks and concentrates the sugars. One plant gives 6–12 fruit.

Also known as: Papryka, Pimiento / chile, Pepper, Pimento / pimentão (BR), Capsicum annuum, Paprika, Piment / poivron

How to grow sweet pepper / bell pepper

1
Sow seed indoors
Late February to mid-March in a heated propagator at 21–25°C. Sweet peppers need a long season; later sowings rarely ripen before autumn cools off. Sow 2 seeds per 9 cm pot, 5 mm deep; thin to the strongest seedling after germination.
2
Pot on as roots fill
Move to 1-litre pots when roots fill the smaller; then 5-litre pots once the plant is 30 cm tall. Don't let pepper seedlings get root-bound — they check growth and never fully recover.
3
Choose UK-suitable F1 hybrids
Bell Boy (classic blocky bell), Redskin (compact dwarf for containers), Sweet Banana (long, mild, very productive), Marconi (Italian pointed type). F1 hybrids out-perform open-pollinated peppers in UK conditions by a wide margin.
4
Plant in final position by late May
Greenhouse / polytunnel border or 7.5-litre containers. Outdoor in sheltered south-facing pots from June only. Indoor positions get earlier and bigger crops.
5
Pinch out the growing tip
When plants are 30 cm tall, pinch out the top growing point. This encourages branching and gives a bushier plant with more fruit. Bell Boy and dwarf F1s self-branch and need less pinching.
6
Feed and water
Feed weekly with a high-potash liquid feed from the first flowers. Water consistently — peppers are prone to blossom-end rot from erratic watering. Avoid splashing the foliage to reduce mildew.
7
Pick green or wait for colour
Sweet peppers are fully edible when green but sweeten as they turn colour over the final 2–3 weeks. Picking green keeps the plant productive for longer (more fruit, smaller); leaving fruit to colour gives fewer, sweeter peppers. Most UK growers do both.
8
Watch for aphids and mildew under glass
Greenhouse pepper plants attract aphids; encourage ladybirds and hoverflies, or wash off with soapy water weekly. Powdery mildew strikes in late summer — improve airflow by removing some leaves around fruit.

Common questions

Pest Resilience

3/5 — Average

Aphids, red spider mite under glass, and blossom end rot (cultural issue).

Companion Planting

Grows well with

Herb basil sweet Marigold Onion

Keep apart from

Fennel bulb Fennel perennial

Visual Characteristics

🍳

Culinary

Culinary Use

Stir-fries, stuffed, roasted, salads, fajitas, sauces, salsas

The sweet pepper / bell pepper year in your garden

Dispatching imaginary bots to check your garden out...

What to do now

How to Propagate

🌰Seed

Easy

Hardiness Zones

H1a (tender)H7 (very hardy)

H1a

H1b

H1c

RHS H1c

USDA 10–11 equivalent