IT’S BEEN a bit too hot for chillies this year, which is something I wouldn’t have expected to write about a British summer a few years ago.

All species of capsicum, including sweet peppers, need plenty of warmth to grow well, but too much heat — experts say anything above 30°C — and their ability to produce fruit may be reduced. I usually raise mine in a conservatory, from seedling right through to harvest, but by early June the temperature in there was routinely topping 38°C and the plants were visibly struggling, so I moved them to my unheated greenhouse.

Even in the greenhouse, with its special ventilation features which the ignorant might mistake for broken panes that I can’t afford to replace yet, neither my chilli peppers nor my sweet (or bell) peppers are cropping as prolifically as they usually do. I’ve heard the same complaint from those who grow compact varieties on sunny windowsills.

At least it’s easier in a greenhouse to keep the air sufficiently humid to suit chillies than it is indoors: empty a watering-can over the floor every day and let the water evaporate. Putting pots of chillies outside through the hottest months often works, though wind or heavy rain or a brief drop in temperature might find you doing the hokey-cokey, rushing the pots in and out again as conditions change.

Now that autumn’s arrived, and the nights are much cooler in the greenhouse, I’d like to bring my chillies back inside to finish ripening. They’re in pots, not in the border soil, so that should be possible. The problem is that the varieties I’m growing make quite large, multi-branched plants, and manoeuvring them out through the greenhouse door and into the house without knocking the fruits off or snapping the stems would be difficult. Not to mention undignified.

The answer is probably to pick the chillies green and preserve them for winter by freezing, dehydrating and pickling. Capsicums are well suited to all three methods. Both kinds of pepper, the hot and the sweet, are perfectly edible at the unripe, green stage, and many people in fact prefer them that way. Just check that they have reached a proper size for their variety and that they are firm to the touch.

Choosing whether to let chillies fully ripen or not is, even in what used to be a normal summer, a matter of balance. Like most gardeners, I tend to take some early and some late. Pick them unripe, and the plant will continue producing more — you’ll get a considerably smaller crop if you let all the fruit reach full maturity. 

Sweet peppers become much sweeter when ripe, and chillies hotter. In both cases it’s probably fair to say that fully coloured fruits have a more complex flavour. To a degree, unripe peppers, if they’re full size, will continue ripening off the plant in a warm room, but they won’t usually develop the full depth of piquancy found in those matured naturally.