Traditionally gardeners have treated sweet peppers and chillies as annuals, allowing the frost to kill them in the winter and resowing them in the Spring. However most chilli varieties actually overwinter very well and will produce a larger and earlier crop the following year and for several years on the same plant.
Generally speaking smaller leaved and dwarf chillies are the easiest to over winter. Our most popular windowsill chilli, the ‘Apache’ is brilliant for this and we have customers now who have 4 and 5 year old apache chilli plants and they are still going strong. The trick is to keep them above freezing either on a sunny windowsil or in a heated greenhouse and start to cut back on the watering after you’ve harvested the last fruits. Whether this is November or February, you should take your cue from whether your plant is starting to put on new shoots and flowers or not. If it isn’t, then take this opportunity to let it rest.
Try to hold back on watering and feeding until the top of the pot is quite dry to the touch and the leaves have even started to wilt a little. Then taking sharp seceteurs, it’s time to give your plant a trim. You want a nice stocky shape for next year so cut back to the 2nd or 3rd node point. On an apache chilli this might be a couple of inches about the soil but on the taller friars hat in the photo below it was a good 3ft from the soil level.
This looks drastic but will do the plant good long term. At this point the last of the old leaves will normally start to wilt and fall off and not very much will happen for a couple of months. Keep an eye on them though, around the end of March you should start to see very tiny leaf buds developing on the old nodes as your plant starts to wake up for spring. If your chilli plant is growing it needs water – an egg cup full the first day and then another when the first leaves start to open, before returning to a regular watering every time the top of the soil dries out.
Because we have such a demand for early fruiting chilli plants we always over winter a late crop of chilli plants to get the season off to an early start. In 2012 the weather was so bad in the early part of the season that the only plants we had with colouring fruit in July were overwintered cayenne chillies. This year as a precaution we have therefore overwintered apache chillies, twilight chillies and friars hats to try and ensure we will have a nice colourful display for our Grow Your Own Curry Display at Hampton Court this summer. At the moment, writing in May we’re so glad we did, but will even that be enough! Fingers crossed for some sunshine now…