When to Plant Peppers in the UK
Sweet peppers are slow to get going and need months of warmth to ripen, so in the UK, timing is everything. They're sown earlier than most vegetables, grown on indoors for weeks, and only moved to their final spot once it's properly warm. Get the dates right and you'll be picking glossy peppers from midsummer into autumn.
Quick answer
For plants that will grow in a greenhouse, sow seeds indoors from mid-February to early March. For plants going outside, wait until the end of March or early April. The seeds need 18–21°C to germinate. Plant them into a heated greenhouse in late April, an unheated greenhouse in mid-May, or outdoors in late May or June, once nights stay above 12°C.
Pepper planting calendar
Mid-February to early March: sow seeds indoors for plants that will grow in a greenhouse.
Late March to early April: sow seeds indoors for plants that will grow outdoors.
March to May: move seedlings into bigger pots as they grow, and keep them warm and bright.
Late April: plant into a heated greenhouse.
Mid-May: plant into an unheated greenhouse or polytunnel.
Late May to June: plant outdoors, after hardening off.
July to October: harvest.
Why peppers are sown so early
Peppers grow slowly, especially in their first few weeks, and they need a long run of warm weather to flower and ripen their fruit. Starting them early indoors gives them the time they need. Sowing too late, particularly for plants grown outside, often leaves you with fruit that's still green and small when autumn arrives.
At the same time, there's no benefit in sowing much earlier than February. Seedlings struggle in the short, dark days of midwinter and can become weak and leggy.
Sowing pepper seeds
Fill small pots or a seed tray with peat-free seed compost and water it.
Sow the seeds thinly on the surface and cover them lightly with compost.
Keep them warm, at 18–21°C. Use a heated propagator if you have one. Otherwise, put the pots in a clear plastic bag on a warm windowsill above a radiator.
Once the seedlings come up, remove the cover and keep them in bright light at around 16–18°C.
When each seedling has two true leaves, move it into its own pot, around 7.5–9 cm across.
Move the plants into bigger pots as their roots fill each one. Keep them in the brightest spot you have so they grow sturdy rather than tall and weak.
Other crops worth starting early are listed in when to start vegetable seeds indoors
Planting in a greenhouse
A greenhouse gives peppers the warmth they need and produces the most reliable crops in the UK.
Heated greenhouse: plant from late April.
Unheated greenhouse or polytunnel: plant from mid-May.
Grow them in the greenhouse border, in pots at least 30 cm wide, or two or three to a standard grow bag. Space plants about 38–45 cm apart, or 30 cm for compact varieties.
Planting outdoors
Peppers can grow outside in sheltered, sunny gardens, especially in the south, but you'll need to wait for warm nights. According to the RHS, 12°C at night is the minimum they'll tolerate, and they do noticeably better when it stays above 15°C. In most years, that means late May or June.
Harden plants off for about two weeks first: start with a few hours outdoors on mild days and build up gradually. A sheltered patio in front of a sunny wall is ideal. Keep some fleece handy for chilly nights.
For varieties that cope with outdoor growing or an unheated greenhouse, the RHS recommends 'Redskin', 'Mohawk' and 'Corno di Toro Rosso'.
Last frost dates for each region are in when to plant vegetables in the UK
For hardening off, see how to harden off seedlings
Buying young plants instead
No propagator or bright windowsill? Garden centres sell young pepper plants through spring and early summer, which saves you starting from seed. Plant them out on the same dates as home-raised plants.
When will peppers be ready?
Peppers planted in spring are usually ready to pick from July or August into October. They're ready once they've filled out and the skin is glossy. You can harvest them green, or leave them on the plant to ripen to red, yellow or orange, when they're sweeter. Picking the first few fruits while they're green also encourages the plant to produce more. See when to harvest peppers
Is it too late to plant peppers?
Seeds sown after April rarely have time to ripen fruit, particularly outdoors. If you've missed the sowing window, buy young plants in late spring. In September and October, it's harvest time rather than planting time. Bring any peppers in pots into a greenhouse or conservatory to help the last fruits ripen before the cold weather.
Growing peppers in pots
Peppers grow well in containers, which you can move to the warmest spot in the garden or under cover when the weather turns. Use a pot at least 30 cm wide. Our peppers in pots guide has the details.
Watering, feeding and everything else are covered in how to grow peppers in the UK. Plants not doing well? Try why peppers don't grow. Chillies follow a very similar calendar, which you'll find in when to plant chillies in the UK
Common questions
When should I sow pepper seeds in the UK?
Mid-February to early March if they'll be grown in a greenhouse. For peppers that will grow outside, sow a few weeks later, at the end of March or early in April.
When can I plant peppers outside in the UK?
In late May or June, once nights stay above about 12°C. Harden them off gradually for about two weeks beforehand, and plant them somewhere warm and sheltered.
When should I put peppers in the greenhouse?
From late April in a heated greenhouse, or from mid-May in an unheated greenhouse or polytunnel.
Can I grow peppers outside in the UK?
Yes, in a warm, sheltered spot, especially in southern areas. They crop more reliably under glass, so choose varieties suited to outdoor growing, such as 'Redskin'.
Sowing and planting dates based on RHS guidance.