How to overwinter chilli plants in a cool climate: which to keep, how to prune and pot them, the temperature, light and water they need, and how to restart them in spring.
The short answer¶
Chillies are perennials in their native tropics. In a British winter they die only because of cold, not old age, so a plant brought indoors before the first frost can live for several years. In October, cut the plant back to a framework of main branches, repot it into a slightly smaller pot of fresh compost, and keep it somewhere bright and frost-free, ideally 10–15 °C, watering only sparingly. In February or March, move it into warmth and light and start feeding. An overwintered plant starts the season with a full root system and a woody frame, so it flowers and fruits weeks earlier than a new seedling — especially valuable for slow Capsicum chinense types such as habanero and scotch-bonnet.
Why bother¶
- An earlier, bigger crop. An established plant flowers in spring rather than midsummer.
- Slow varieties. Superhots like ghost-pepper and carolina-reaper can struggle to ripen in one British season from seed. A second-year plant has a head start.
- Keeping a favourite. A plant that has done well, or one grown from saved seed that may not come true, can be kept going.
- Rocoto and other C. pubescens. These often fruit best in their second year.
It is less worthwhile for cheap, fast varieties that you can resow each year, and for plants that have been heavily infested with pests.
Step by step¶
- Choose healthy plants. Check under leaves and at shoot tips for aphids, whitefly and red spider mite. Heavily infested plants are best composted.
- Bring them in early. Aim for early to mid-October, or earlier if frost is forecast. Harvest any remaining fruit.
- Prune. Cut back to the main stem and a few strong branches, leaving a Y-shaped or three-branched framework roughly 10–20 cm above the pot. Cut just above a node. Remove most or all of the leaves; this reduces water loss and pests.
- Repot. Tease away some of the old compost and trim back very long roots, then pot into a pot one or two sizes smaller, using fresh compost. This reduces the volume of cold, wet compost that can cause root rot.
- Clean up. Rinse the stems or wipe them down to remove hitchhiking insects. Many growers keep newly pruned plants apart from houseplants for a week or two.
- Place. A bright windowsill in a cool room, a heated greenhouse or a conservatory kept frost-free.
Winter care¶
| Factor | What the plant needs |
|---|---|
| Temperature | Ideally 10–15 °C. Below about 5 °C, damage is likely; frost kills |
| Light | As much as possible. Growth will be minimal; that is fine |
| Water | Only when the compost is nearly dry — perhaps every two to four weeks in a cool room |
| Feed | None until spring |
| Humidity | Avoid hot, dry air above radiators, which favours red spider mite |
The aim is dormancy, not growth. A plant kept warm but in low winter light will produce weak, pale shoots that are magnets for aphids. If that happens, pinch them out.
💡 Warm rooms
If the only space you have is a warm living room, the plant will not go dormant. Keep it on the brightest windowsill, water a little more, and be vigilant for aphids. Consider a grow light. Many plants survive this way, though they are less tidy than cool-overwintered ones.
Waking up in spring¶
From February to March, as days lengthen:
- Move the plant somewhere warmer (18–24 °C) and as bright as possible.
- Increase watering gradually as new shoots appear.
- Once it is growing strongly, pot on into its final summer pot with fresh compost.
- Start a balanced feed, switching to a high-potash tomato feed when flowers form.
- Harden off and move outside or into the greenhouse as you would for a new plant (see growing chillies).
New shoots usually appear from buds along the pruned stems within a few weeks of warmth.
Pests: the main risk¶
Most failures in overwintering come from pests rather than cold. Aphids breed without males over winter indoors and can build up fast on soft new growth. Inspect plants weekly, squash or rinse off colonies, and remove badly affected shoots. Sticky yellow traps help to monitor whitefly and fungus gnats. Fungus gnats are also a sign of compost that is too wet.
How long will a chilli live?¶
With care, several years. Stems become woody and bark-like, and the plant takes on a small tree shape. Plants do become less vigorous with age, and after three or four years many growers prefer to start afresh from seed. Some enthusiasts grow chillies as "bonsai", keeping them compact by root and shoot pruning, which relies on the same principles described here.
Common mistakes¶
- Waiting until after the first frost. Even a light frost can kill the top growth.
- Overwatering in winter. Cold, wet compost causes root rot, the commonest cause of death.
- Leaving the full canopy of leaves on. It drops anyway and brings pests in with it.
- Starting feeds in winter, forcing weak growth.
See also annual and perennial herbs for other tender plants that need the same treatment.