Late winter to spring indoors with warmth; early sowing needs a bright growing-on space.
Late spring or early summer, once reliably warm conditions are available.
Summer to autumn. Colour and flavour change as fruits ripen.
Choose for your season
Compact, earlier varieties are often easier to ripen in a UK greenhouse than very late types. Sweet peppers and chillies share many growing needs, but fruit size, plant vigour and maturity dates vary widely.
Start with warmth and light
Use fresh seed compost and the germination temperature on the packet. Germination may be uneven, so allow time. After emergence, provide good light and continued warmth rather than leaving seedlings in a dark, hot propagator.
Grow steadily
Pot on as roots develop and support heavily laden plants. Water when the compost needs it, allowing drainage rather than standing pots in water. Feed according to the product instructions as fruits develop. Ventilate on bright days.
Pick and overwinter
Harvest green or allow fruits to colour as the variety permits. Wear gloves when handling hot chillies and avoid touching your eyes. Overwintering needs a suitable warm, bright space and careful pest checks; it is not guaranteed in an unheated greenhouse.
Plan the next step
Keep a weekly record of watering, feeding and harvests. Note your overnight minimum temperature: this is more useful than the warmest afternoon reading when deciding whether a tender crop can move into an unheated greenhouse.
Read the monthly growing calendar, watering and feeding guide and plant health guide alongside your seed packet.
Further reading: RHS greenhouse vegetables.
What’s happening in your greenhouse?
Ask a growing question or share your experience. Comments and replies are checked before publication.
Loading approved comments…