
Capsicum annuum
Sweet peppers are tender annuals that produce crisp, colourful fruits with a mild flavour. Native to Central and South America, they thrive in warm, sunny positions and are commonly grown under glass in the UK to ensure reliable cropping, though they can succeed outdoors in sheltered spots during particularly warm summers.
Step-by-step instructions for growing Sweet Pepper
Change the guide to see different planting timelines and tips.
Step by step guide to growing sweet peppers in a greenhouse or under cover.
Fill seed trays with peat-free seed compost and sow your seeds about deep. Cover lightly with compost and water gently from below to avoid disturbing the seeds. Place in a heated propagator or on a warm windowsill at to encourage germination.
Once seedlings have their first true leaves, carefully transplant them into individual pots filled with peat-free compost. Handle by the leaves to avoid damaging the stems, and firm in gently. Keep in bright light at or above and water regularly.
When roots start to show through the drainage holes, move the plants into larger pots with multi-purpose compost. This gives them room to grow stronger before final planting.
Plant out into the greenhouse border or large pots when night temperatures are reliably above . Space plants apart and provide supports like canes for taller varieties.
Once plants reach about tall, pinch out the growing tips to encourage bushy growth and more side shoots for better fruiting.
As soon as the first flowers appear, start feeding weekly with a high-potash liquid fertiliser like tomato feed to promote healthy fruit development. Keep the compost evenly moist but not waterlogged.
Pick peppers when they reach full size, starting green for a crisper taste or leaving to ripen to red or yellow for sweeter flavour. Regular harvesting encourages more fruits to form.