Overwintering Chilli Plants : Kent Chilli Garden

Overwintering Chilli Plants

There are several methods of bringing chilli plants through the winter, most heavily dependant on what facilities you have - light, temperature, and available space (if you have to bring them inside) being the main ones. The method described here presumes that you live in a climate with a winter that will not support chilli plants, and is one that puts the plants into a dormant state for the winter. It is the method we use at Kent Chilli Garden, with pretty good success.

Some of this may seem a little obvious (and other bits less so) but we’ll go through it step by step.

Description: C:Documents and SettingsMikeMy DocumentsChillisoverwinter pics2013-10-13 14.50.44.jpgFirstly, only select the strongest healthiest plants to overwinter. There’s no point taking a weak diseased plant through to next year. Its chances of surviving the winter are much reduced to begin with, and if it does the resulting plant next season will not be the best. Choose a better one! Here you can see a 7 pot primo ready for the chop (looking a little yellow towards the end of the season)

Next remove any remaining chilli pods, including the unripe ones. Depending on the type, some pods are excellent eaten before they are ripe. Others not so much so, but pods can to some extent be ripened off the plant.

Now comes the scary bit! You’ve just spent best part of a year lovingly cultivating this plant into a big beautiful specimen, but now it’s time to hack it to pieces! Prune away all side shoots and upper branches, leaving little more that a stick. I follow up the main stem, past where it forks, and then past where it forks again, and cut off everything above this about 3 inches past the second 2 forks. This will leave you with an upright stalk with 4 ends. If you have any large leaves on the stalk, remove those too.

The next bit is optional, but I have good success and it makes maintenance throughout the winter easier. I also prune back the roots. Remove the plant from its pot and shake away excess soil, then trim back the roots. The original size of the plant will determine just how much you cut back. For larger plants – ie those that fill up 45litre pots, I cut the roots back to about the size of a football. Smaller plants I cut back further still, so that they fit into half a 2 litre plastic coke bottle. That’ll make sense in a minute. The thing is to balance the size of the pruned plant and its rootball, so that the roots are enough to keep the plant alive through the dormant period without wasting energy on being excessively large.

The whole point of this exercise is to allow the plant to conserve energy over the winter, and by taking away all the foliage it removes the need for the plant to expend energy maintaining it. Exactly the same principle that deciduous trees use and the reason they shed their leaves in autumn. It works for them!

Once plant and roots are pruned, the bigger plants I re-pot into smaller pots with fresh compost, ensuring good drainage. Water very sparingly over the winter season, allowing the soil to almost dry out before wetting. The plants will take up very little water, and you may not have to water for a couple of weeks at a time.

For smaller plants, I do the following;

Take a standard 2 litre plastic coke bottle (or fizzy beverage of your choice) and cut it in half horizontally. You should then be able to turn the top half upside down and fit it, cap end down, into the bottom half, with the bottle cap removed. You’ve just made a pot and water reservoir!

Now get yourself some capillary matting, and cut a section so that it fits into and lines the top half of the bottle, and has a wick that goes through the bottle top and reaches into the bottom of the reservoir.

Your newly trimmed plant should fit snugly into the top half of the bottle, and the bottom half can be filled with water. The capillary matting will provide enough water to the plant to keep watered, but not too wet, throughout the winter. You will find that you will have to change the water long before it runs out, but doing this weekly should be sufficient to prevent algae and parasites.

A couple of tips – covering the bottles in something dark, or by putting them in a box to block out light to the reservoir and roots, will help prevent algae growth in the water. Also filling the top of the bottle with a layer of sand helps to stop pests and mould in the soil of the plant.  

Whether in a pot or bottle, do not feed the plants over the winter – plain old water is just fine.

Now that’s all taken care of, to give your plants the best chance of surviving the winter, do not let them get too cold – but likewise keep them well away from heat sources like radiators and suchlike. As a rule I never let ours drop below 10 degrees centigrade, and never anything above normal room temperature. 14 to 18 is ideal. Be aware that rises in temperature and exposure to prolonged levels of bright artificial light can confuse the plants, making them think it is spring and wake up trying to grow. You do not want to stress your plants by having them keep start and stopping growing, so by keeping them cool (but not cold) and out of direct sunlight and away from strong artificial light (but not dark) you can prevent this from happening. You get the idea… Conservatories are ideal.

As spring arrives and light levels increase and temperatures rise, your plants will start to wake up and put out new leaves. It may take a while to get going, but once they do it’s time to re-pot into larger containers, with fresh compost. You will generally find that plants will not continue growth from the ends of the trimmed stem, but rather put out side stems from along its length from base to tip. This creates a much bushier plant that is likely going to need support, or it can end up a bit of a busy mess that is easily damaged. Tie and support it though and you’ll have a strong healthy plant, which will more than likely produce far more pods the second year around.

As an added bonus, if the mood takes you, you could also use your overwintered plant as a “mother” plant. This term refers to a plant that you keep growing to provide cuttings so you can clone more plants from it. Of course you can take cuttings from a plant at any time, but this is the ideal tine to start.

As the new shoots grow from your overwintered plant, wait until they have at least half a dozen leaves on them and a stem of a couple of inches, then trim them carefully off using a sharp knife. Remove the lower pair of leaves, leaving only 4. Also, if any of these leaves are particularly large, it’s a good idea to cut them in half – much like overwintering, by removing a proportion of foliage you reduce the amount of energy the plant has to provide to the leaves until it has the root system to support it. Now place the stem snugly into a rockwool cube in your propagator. You could also dip the stem into a rooting hormone before placing it in the cube. This may help it establish roots more quickly, but is not essential. Now mist it regularly with water - or better still a very mild nutrient solution. HESI Root complex is particularly good for this. The cutting will absorb moisture and nutrients through the leaves until it has developed roots so this is quite important! Pretty soon it will put out a root system, and when this is showing at the edge of the cube, it’s time to pot on and treat as a new plant. And if you have 8 out of 10 cuttings survive, that’s 8 brand new plants! Not a bad way of expanding the number of your favourite chillies.

We hope you find this guide helpful. It is a great way to preserve your favourite chilli plants, and allow you to concentrate your new seed growth on new varieties. If there is anything that we've missed or is not clear, or if you have used other methods with success that you'd like to share, please get in touch.

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