Overwintering chilli plants: how to keep chillies alive in winter

Although the fiery chilli prefers warmer climates, it can survive our winters. Here is our guide on how to successfully overwinter chillies.

At home in South and Central America, chillies (Capsicum) are used to a lot of sun and warmth whereas here, they need to deal with cold and frosty winters. Since the plant is not accustomed to such temperatures, there are several points to consider when overwintering chilli plants. We will show you at which point it gets too cold for the chilli and how you can overwinter chillies in the garden and in pots.

As chillies are sensitive to frost, they are usually grown as annuals. But this does not have to be the case because chillies, unlike tomatoes (Solanum lycopersicum) for example, are perennial plants. Kept in the right spot, chillies can even bear fruit all year round. They belong to the nightshade family (Solanaceae) and the Capsicum genus and there is an unbelievable number of chilli varieties worldwide, which are assigned to five Capsicum species. Read on for our tips and tricks on how best to overwinter your chillies and to make the most of these flavoursome fruits even in winter.

Overwintering chilli plants: when is it too cold?

Chillies love heat and die in light frost. If temperatures drop below 14 °C at night, the chillies’ growth rate declines. From temperatures permanently below 10 °C, most chilli varieties lose their leaves and look sickly and unhealthy. The chilli species Capsicum Chinese is extremely sensitive to cold and cannot tolerate temperatures below 13 °C. Rocoto chillies, on the other hand, are quite tolerant. Chillies of the species Capsicum pubescens, to which the rocoto chilli belongs, can survive night temperatures as low as 8 °C.

How to overwinter chilli plants

Since temperatures can drop well below 10 °C even in autumn, it is almost impossible to overwinter chillies outdoors. The only way to overwinter chillies in the garden is in a heated greenhouse. Here you can regulate the temperature and ensure that your chillies never get too cold throughout the winter months.

Overwintering chillies in pots

It is much safer to overwinter chillies in a pot as you can ensure they stay warm enough. Make sure to leave the chillies outside in a sheltered place for as long as possible. Once the temperature remains consistently low, it is time for the plant to move indoors. Ideally, overwinter your chillies in a cool, bright room with temperatures between 10 and 15 °C. Make sure the temperature never goes below 10 °C.

If the chilli is overwintered in a cool spot, it will not bear any fruit during this time but can save energy for the new season during its winter dormancy. Alternatively, you can overwinter your chillies in a warm, sunny location – for example in a bright conservatory, a heated greenhouse or on a warm sunny windowsill. The temperatures here must not exceed 20 °C and the light and temperature conditions need to remain consistent throughout the winter. Too little light will cause the plant to wither. There is a chance then that the plant will continue to flower and bear fruit during the winter months. Please note that the chilli is much more susceptible to pests, especially spider mites, if it is kept warm over winter.

Overwintering chillies:

• Cool and bright is ideal
• Temperatures between 10 – 15 °C
• Never frost or temperatures below 10 °C
• Alternatively overwinter at 20 °C max

Caring for chilli plants in winter

Proper care during the winter months is very important. When you bring the chilli plant indoors, the soil in the pot will need to be as dry as possible. If the soil is too wet, the roots can quickly become mouldy. If you are keeping your chilli plant in a warm location over the winter, make sure to water it regularly and to spray it with water as chillies like humidity-levels of over 50 %. If the humidity is too low, the plant can quickly dry out and if the humidity is too high, this can promote mould and pest infestations. It is a good idea to check your chilli for pests regularly. Aphids and spider mites are especially fond of chillies, even in winter. Chillies also do not like warm dry air. Regularly remove dry or dead plant parts. The plant requires less care if it is kept in a cool place during the winter: simply make sure the soil in the pot is never wet but dry to slightly moist. Do not let the pot dry out completely and do not fertilise at all in winter.

Summary of caring for chillies in winter:

• Do not let the soil get too moist but do not let it dry out either
• Stop fertilising
• Spray with water regularly
• Keep humidity above 50
• Check the plant for pests regularly

Once winter is over, you can slowly prepare your chillies for the summer. From mid-February to the beginning of March, the plants can be placed in a slightly warmer location and be watered more frequently. Also, prune and repot the chilli in spring.

Once your chillies have been successfully overwintered, a new summer and a new chilli harvest are in store.