Fruiting vegetable
How to grow chillies
Capsicum annuum / C. chinense
Chillies need a long, warm season, so sow early: January to March at 25 to 28 °C in a propagator, with the hottest types first. Pot on in stages into a final pot of up to 10 litres and grow them in a greenhouse, polytunnel or on a sunny windowsill, since few crop well outdoors away from a warm wall. Start top-dressing with a high-potash feed when the first flowers open and keep watering steady.
- Hardiness
- Tender
- Position
- Full sun, warm, ideally under glass
- Soil
- Free-draining, fertile
- Ideal pH
- 6.0 to 6.8
- Water
- Moderate, slightly drier than sweet pepper; never waterlog
- Feeding
- Heavy feeder
Sowing and planting chillies
WhenSow Jan to Mar with heat (hot types earliest); plant out May to Jun; harvest Jul to Oct
Starting off
Sow indoors from January (habanero and other Capsicum chinense types) to March, 0.5 cm deep at 25 to 28 °C in a heated propagator; germination takes 7 to 14 days for C. annuum, up to 4 weeks for hot types. Grow on at 18 to 20 °C under good light, pricking out into 9 cm pots and potting on twice before planting in May.
Spacing and planting
Plant 40 to 45 cm apart in a greenhouse border or one per 20 to 30 cm pot: a 2 litre pot gives a small, early crop, a 10 litre pot a bigger plant. Plant at pot depth and stake taller types with a 60 cm cane. Compact types such as 'Apache' crop well in a 20 cm pot on a windowsill.
Varieties worth growing
- Apache F1
- Compact, early and medium-hot; crops on a windowsill in a 20 cm pot.
- Hungarian Hot Wax
- Mild to medium, ripens from yellow to red, the most reliable outdoors in a cool summer.
- Jalapeño 'Early'
- Medium heat, thick-walled for stuffing and pickling, sets well under glass.
- Cayenne
- Long thin hot pods that dry on a string; prolific in a greenhouse.
- Habanero (Capsicum chinense)
- Very hot and fruity but needs a January sowing and a heated greenhouse to ripen in the UK.
Chillies month by month
Timings are for central England. Allow two weeks later in the north and on cold, heavy soil.
- January
Sow habanero and other Capsicum chinense types in a heated propagator at 25 to 28 °C.
- February
Sow most C. annuum types with heat. Keep under a grow light or the brightest window.
- March
Last sowings. Prick out into 9 cm pots at the two-leaf stage.
- April
Pot on into 1 litre pots. Grow at 18 to 20 °C.
- May
Plant into final pots or the greenhouse border mid month. Pinch the tip of lanky plants at 20 cm.
- June
Harden off outdoor plants, plant out after mid June in a sheltered sunny spot. No extra feed until the first flowers.
- July
First flowers: start top-dressing with Chilli Fertiliser every 2 to 4 weeks. Stake tall types.
- August
Pick green pods to keep the plant setting more. Shade glass above 30 °C.
- September
Let pods ripen to full colour for heat. Reduce watering slightly.
- October
Pick everything before frost; ripen on a sunny sill. Pot up plants to overwinter.
- November
Overwinter chosen plants at 10 °C, cut back by half, water sparingly.
- December
Order seed. Overwintered plants stay dry and cool.
Feeding chillies
Moderate feeder with a potash lean. Too much nitrogen gives a big leafy plant and no pods.
Balanced while growing, switching to high-potassium at flowering. Go easy on nitrogen, lush plants set fewer pods.
Feeding plan
Potting into the final pot
Chilli & Pepper Fertiliser 3-3.5-7
5 to 10 g per litre of compost: 50 to 100 g in a 10 litre pot, half that if you also use mycorrhizal powder.
Planting, greenhouse border
Chilli & Pepper Fertiliser 3-3.5-7
A handful (50 g) in each planting hole, 40 to 45 cm apart.
Every 2 to 4 weeks from first flowers
Chilli & Pepper Fertiliser 3-3.5-7
1 to 3 g per litre of pot volume scattered on the surface and watered in: 10 to 30 g for a 10 litre pot. This is the only feed the plant needs after potting.
Sunken black pod ends
1 to 2 g per litre of water as a drench every 2 to 3 weeks, and fix the watering.
At potting, optional
5 g per litre of root-ball volume dusted on the roots, once.
Signs to watch
Flowers dropping without setting
Temperatures over 30 °C or below 15 °C, or excess nitrogen, not a nutrient shortage
Shade, ventilate and switch to high-potash
Sunken black patches on pod ends
Blossom-end rot from erratic watering
Water evenly
Older leaves yellow between the veins
Magnesium locked out by high-potash feeding
Epsom salts spray
Pests, diseases and problems
Sticky leaves, curled shoot tips, green insects clustered on new growth
Aphids
Rub off the first colonies, spray with potassium soft soap, and let ladybirds in by opening the greenhouse vents.
Fine webbing between leaves, leaves speckled and bronzed
Glasshouse red spider mite in hot dry air
Damp the greenhouse floor twice a day, mist the undersides, introduce Phytoseiulus mites in June.
White insects fly up when the plant is touched
Glasshouse whitefly
Yellow sticky traps and Encarsia wasps from May; soft soap on the undersides.
Flowers drop without setting
Night temperatures under 15 °C, days over 30 °C, or no pollinator movement
Ventilate on hot days, close up at night, tap the canes at midday to shake pollen, and ease off nitrogen.
Grey fur on stems and pods
Botrytis in a damp, still greenhouse
Ventilate, water in the morning, remove affected pods and leaves.
Harvest and rotation
Harvest and storage
Pick green pods at full size from 16 to 20 weeks after sowing, or leave 2 to 3 weeks more to ripen red for heat and sweetness; cut with secateurs, keeping 1 cm of stalk, and pick often. A plant gives 20 to 50 pods by variety. Dry ripe pods on a string in a warm room, freeze whole, or pickle; overwinter plants at 10 °C.
Rotation and companions
Rotation: potato family (Solanaceae) with tomatoes, peppers and aubergines, 3 to 4 year gap outdoors; fresh compost for pots each year. Keep away from fennel and from brassicas that want cool, limed ground.
Good to knowA long season, so start early indoors; a slightly drier, hotter finish can lift the heat in some varieties.
Growing chillies in pots
Chillies are a pot crop in the UK. A 2 litre pot gives a small early crop, a 10 litre pot a bush that fruits until October; compact types like Apache stay happy in 20 cm. Use a free-draining peat-free compost with a fifth perlite or grit and the Chilli Fertiliser mixed through. Water when the top 2 cm is dry, not on a schedule: chillies are the one fruiting crop that resents sitting wet, and a slightly dry finish in September concentrates heat. Move pots under cover in October and the plant will carry on for another year.
Chillies: common questions
When should I start feeding chilli plants?
Once the plant is in its final pot with the Chilli Fertiliser mixed in, nothing extra until the first flowers. Then top-dress with the same fertiliser every 2 to 4 weeks, 1 to 3 g per litre of pot volume, watered in. Feeding a seedling with nitrogen just delays flowering.
Why are my chilli flowers dropping off?
Temperature, nearly always: nights below 15 °C or days above 30 °C stop pollen working. Ventilate by day, close up at night, and tap the plants at noon. Excess nitrogen is the other cause.
Can I keep a chilli plant over winter?
Yes. Cut it back by half in October, pot it into fresh compost, keep it at 10 °C in good light and water about once a fortnight. It will fruit a month earlier than a seed-sown plant next year.
Sources
Growing information on this page was checked against these references in November 2026. Feeding rates are Dr Forest label rates.
- How to grow chilli peppersRHS
- How to grow chilliesBBC Gardeners' World