Blog: Get a head start next year by saving your favourite plants…
Most people ditch chilli plants in autumn, but they’re perennials – here’s how to overwinter chillies for better crops next year. Only attempt to keep potted plants from one year to the next (most people do anyway). If they’re grown in a greenhouse bed, the root disturbance and damage of being potted up will lessen their chances of survival.
I’m keeping four varieties (I’ve included the heat in Scoville Units, the measurement of heat in chillies). Read more on this topic and growing chillies from seed, and growing super-hot chillies.
- Biquino Red (very mild, sweet, tiny Brazilian, 50 SHU)
- Razzamatazz (multi-coloured, prolific, medium heat, 5,000-20,000 SHU)
- Trinidad Moruga Scorpion (second-hottest chilli in the world, 1,200,000-2,000,000 SHU). I’m not daft enough to eat it, it’s for my stepson!
- An unnamed long red mild variety, which was a gift and has previously been overwintered.
How to overwinter chillies – why try to overwinter plants?
There are several advantages:
- Next year’s harvest will be earlier, produce more fruits and over a longer period. This is useful for varieties such as naga or habanero that can have a very short fruiting season when young
- They’ll have established rootballs and will burst back into life, producing new leaves when the days lengthen
- You’ll save money buying seeds
- Overwintered plants will have a massive head start over seeds sown in late winter/early spring
- Some are easier than others – Habaneros and Cayenne overwinter easily, while Jalapenos are a challenge.
When to start overwintering
When the temperature drops below 10°C at night under glass (about the end of October), plants start to shut down for the winter. Growth virtually stops, drastically reducing light and water needs. Pick off all the ripe chillies, as this sends a signal to the plant that it will need to produce more fruit next season.
Heat and light levels
Plants must be overwintered in an environment warm enough for humans – a south-facing window is ideal. Don’t let plants touch the glass or trap them behind curtains on cold nights. Light levels are much better in a conservatory, but the temperature is lower than in the house, so my plants are sitting on a heat mat set to 10°C. It’s thermostatically controlled, so it only comes on when it needs to.
Pruning and potting
Plants also need to be pruned, although there’s some debate as to by how much. Some experts say cut back stems by 10-15cm, others just to cut back any dying branches to where the wood is green, and yet more say prune plants right back, leaving a short stem to concentrate the plant’s energy. Take your pick!
Some people recommend repotting plants in slightly smaller containers but mine are staying put, as this seems to contradict the root damage advice given above.
Watering and feeding
At this time, the plant will virtually stop growing, reducing light and water needs drastically, while preparing for winter. The need for fertiliser also stops. Only keep the compost barely moist – check weekly, but they may only need watering once every 2-3 weeks. Watch out for any mould growth. Use a moisture tester if you’re unsure – keep the soil at about 25 per cent moisture.
How to overwinter chillies – possible problems to watch out for
- Aphids: They make a beeline for chillies, especially in winter, so check plants regularly. If you find any, wash or spray with organic pest killer.
- Dropping leaves: A natural response to the low temperatures and light levels of winter.
How to overwinter chillies – starting plants back into growth
In March, when there are equal hours of daylight and darkness, repot plants in a multipurpose, peat-free compost. Remove any loose old compost from around the rootball. Using the same pot or a slightly bigger one, pot it up and water in well. As warmth and light increase, the plants will start to grow and produce new leaves. Increase watering and after a month, start fertilising again.
A good site to choose seeds from is South Devon Chilli Farm.
