RHS Growing Guides
How to grow chilli peppers
Our detailed growing guide will help you with each step in successfully growing Chilli Peppers.
Getting Started
Growing your own chillies means you can enjoy a huge array of colours, shapes, flavours and levels of heat – a much wider range than you could ever buy in supermarkets. These tender plants grow best in a greenhouse, but can also be grown outdoors in a sunny spot, in pots or in the ground.
There’s a wide array of chillies to choose from if you grow your own from seed
Month by Month
| J | F | M | A | M | J | J | A | S | O | N | D | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sow | ||||||||||||
| Plant Out | ||||||||||||
| Harvest |
Choosing
Buying chilli seeds can be irresistible, with so many colourful varieties and different flavours
Chilli plants vary in size from as little as 20cm (8in) tall and wide (ideal for a windowsill) up to 60cm (2ft) or more, depending on the variety, so select to suit your growing space. Also look for varieties with an RHS Award of Garden Merit (AGM), which shows they performed particularly well in our trials – check out our list of AGM fruit and veg and our Recommended Varieties below. You’ll also see lots of colourful chillies growing in the veg plots at the RHS gardens over the summer months, so do visit to compare varieties and pick up growing tips.
What and where to buy
Chilli seeds are widely available in garden centres and from online seed suppliers. There are also many specialist chilli seed retailers, who offer the widest choice of varieties.
Many of these suppliers also sell young plants in spring and early summer. These are handy if you don’t have time to sow seeds or don’t have a suitably warm, bright place indoors to raise good plants. Another option is to buy grafted plants, which are more vigorous so should produce larger crops, and are especially useful if growing conditions are a little cool. They can be ordered from online suppliers for delivery from mid-April. Many retailers also sell chilli plants already in fruit over the summer months.
Recommended Varieties
F1 hybrid, up to 60cm (2ft) tall. Abundant crop of hot, fiery fruits – 80,000 units on Scoville Scale.
Cayenne type with long tapering fruits. More cold tolerant than most. Hot fruits: 30,000-50,000 SHU.
Up to 200 small, hot chillies per plant – 50,000–70,000 SHU. Plants about 70cm (20in) tall.
Sowing
Carefully lever out individual seedlings...
...and replant singly in modules or small pots
Planting
Chillies grow well in pots, ideally in a greenhouse but also outdoors
Chilli plants grow and crop best in a greenhouse, polytunnel, conservatory or coldframe. Compact varieties can also be grown on a sunny indoor windowsill. In mild locations, you can consider planting them outside too, once night-time temperatures are reliably at least 12°C (54°F), usually by late May or early June. Take care to harden them off for two to three weeks, to acclimatise them to outdoor conditions. Chillies need your warmest, sunniest spot to produce a good crop outdoors, ideally on a sunny patio or by a south-facing wall. Plant them in their new location at the same level they were previously growing in their pot, and add canes to support taller varieties.
To grow in containers, plant one in a 22cm (9in) pot filled with peat-free multi-purpose compost, or plant three in a standard growing bag. See our guides below for more tips.
To grow in the ground, choose a spot with well-drained, fertile, moisture-retentive soil that is ideally slightly acidic. To achieve this, dig in moderate amounts of well-rotted manure, at a rate of 5.4kg (10lb) per square metre/yard, but avoid using fresh manure or large quantities, as this can lead to lush, leafy growth at the expense of fruit. Next, warm the soil with cloches for a couple of weeks before planting. Space chilli plants 38–45cm (15–18in) apart, depending on the variety. Dwarf varieties can be spaced 30cm (1ft) apart. Then cover young plants with cloches to provide wind protection, preferably until the end of June.
Plant Care
Temperature and humidity
Chilli plants can usually cope with a minimum night temperature of 12°C (54°F), but will grow better if kept above 15°C (59°F). However, temperatures over 30°C (86°F) can reduce fruiting, so in hot spells keep the greenhouse well ventilated and put up shading.
Chillies prefer a humid atmosphere, so raise the air’s moisture content in warm weather by ‘damping down’ the greenhouse daily – pour a full watering can over the floor, then leave it to evaporate.
Watering
Water little and often to keep the soil or potting compost evenly moist, avoiding waterlogging and drought. Flower buds may fall off if plants get too dry. Also add mulch to help hold moisture in the soil. Plants in containers can dry out very quickly in summer, so check the compost regularly – see our video guide to watering efficiently.
Feeding
Feed chilli plants with a high potassium liquid fertiliser weekly, as soon as flowering starts.
Overwintering
Pruning and Training
To encourage side-shoots, which should carry more fruit, pinch out the shoot tips once plants reach 30cm (1ft) tall.
Large plants and those in growing bags may need support. Use several canes per plant, and take care when tying in the stems, as they can be brittle.
Harvesting
When growing in a greenhouse, you can usually keep picking chillies well into autumn
Storing
Harvested chillies can be easily dried or frozen, so you can enjoy your crop through the winter too.
Problems
Chillies usually crop best in a greenhouse – when grown outdoors, fruiting may be reduced, especially in cooler summers. Several sap-sucking insects can cause problems, particularly in a greenhouse, so check plants regularly – see below for details. Young chilli plants also need protection from slugs and snails.
Get involved
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