Chilli pepper
Chilli pepper
Capsicum annuum
📋Quick Facts
Height
0.6-0.9m
Spread
0.4-0.5m
Water
💧💧 Average watering
Hardiness
Zone 9-11
About
Sow chilli seed indoors from January to early March — earlier than sweet peppers because hot chillies (Capsicum chinense like Habanero and Scotch Bonnet) need 25+ weeks from sowing to ripe fruit. Chillies are frost-tender (RHS H1c) and want consistent warmth, so a greenhouse, polytunnel, or sunny windowsill is essential in UK conditions. Self-pollinating, so a single plant in a pot crops well. Easy UK varieties: Apache (mild, compact, very prolific), Hungarian Hot Wax (medium), Jalapeño (medium, classic), Cayenne (hot but long season). Pick green for fresh use; leave on the plant to turn red, orange or yellow to develop full flavour and heat. Bring plants indoors in October for a second year — chillies are technically perennials.
How to grow chilli pepper
- 1
Sow early indoors
January to early March in a heated propagator at 25°C. The hotter the variety, the earlier you need to sow: C. annuum (jalapeño, cayenne) from February; C. chinense (habanero, scotch bonnet, naga) from January. Germination 2–4 weeks.
- 2
Choose by heat and season length
For UK conditions: Apache (mild, dwarf, very productive), Hungarian Hot Wax (medium, easy), Jalapeño M (medium, classic, prolific), Cayenne Long Slim (hot but long season), Numex (medium, big fruits). For brave UK growers in a warm greenhouse: Habanero, Scotch Bonnet, Jamaican Hot. Skip Carolina Reaper and similar superhots unless you have a heated greenhouse.
- 3
Pot on through spring
Move seedlings to 9 cm pots once they have 4 true leaves; then 1-litre at 15 cm tall; then final 5-litre pots from May. Don't let chillies get root-bound — they sulk and check growth permanently.
- 4
Final position by late May
Greenhouse / polytunnel border, conservatory, or warm sunny windowsill. Outdoor pots in sheltered south-facing positions from June only — and even then, indoor positions out-produce outdoor by 2-3x.
- 5
Feed and water
Weekly high-potash liquid feed from first flowers. Consistent watering — let the surface dry between waterings; chillies hate waterlogging. Higher heat varieties (habanero) actually develop hotter fruit under slight water stress.
- 6
Self-pollinating but help with a brush
A gentle tap of each flowering plant or a soft paintbrush stroked across the flowers improves fruit set, especially in greenhouse crops with poor air movement.
- 7
Pick green or wait for colour
Most chillies are edible green; flavour and heat develop fully only when the fruit ripens to red, orange or yellow (depending on cultivar). Picking green keeps the plant cropping longer; leaving fruit to colour gives the full flavour. Most UK growers do both.
- 8
Overwinter as a perennial
Chillies are technically tender perennials. Bring plants indoors in October, cut back hard, water sparingly, keep above 10°C. They restart in spring 4–6 weeks earlier than new seedlings — year-two plants give earlier and bigger crops.
Common questions
Pest Resilience
Aphids and red spider mite under glass; capsaicin deters some pests.
Companion Planting
Visual Characteristics
Fruits
Harvest: Summer to autumn / fall
Culinary
Hot sauces, curries, stir-fries, salsas, pickled, sambals, jerk seasoning
The chilli pepper year in your garden
How to Propagate
This plant produces viable seeds for propagation
Hardiness Zones
USDA 10–11 equivalent