THERE’S no such species as the cabbage white butterfly, though you wouldn’t know it from my garden where any brassicas left uncovered during the summer soon have their leaves skeletonised by caterpillars. 

There are in fact two species, the large white and the small white, whose larvae cause such annoyance to veg growers.

By October these butterflies are disappearing from gardens, so there are no more eggs being laid on cabbages, purple sprouting broccoli, kale and the rest. 

Thus, if you’ve had your brassicas covered with netting or horticultural fleece, now is the time to remove it and carry out a little maintenance to prepare these crops for the winter.

The first thing to remember is not to be tempted to feed the plants or the soil they stand in. Any fertiliser applied now will do more harm than good, by encouraging soft growth which would be vulnerable to frost. I wouldn’t do any watering either, unless the ground is still very dry from summer.

If there are dying or dead leaves on your brassicas — yellowing, shrivelled, or just broken — remove them at this stage. They’re of no further use, and might provide overwintering quarters for pests or diseases. 

Take out any weeds that have thrived in the shelter of the netting and remove any leaf litter or general debris from the area around the plants.

Next, firm in the stems of the brassicas, by holding them steady while pressing down on the soil with your boot. Winter winds can cause a lot of losses in these vegetables, unless they have solid foundations. 

After any particularly windy spells from now on it’s worth checking whether that job needs redoing and the same goes for tying taller crops, like broccoli and brussels, to their stakes.

If one of the reasons you net your vegetables is to protect them from birds, especially pigeons, you may be nervous about removing coverings as, unlike insects, birds will remain active after summer. 

On balance, I find it’s still worth uncovering the plants: they’ll benefit from freer movement of air around them, while any caterpillars that have managed to get past the pickets will, once the leaves are revealed, be predated by birds and wasps. 

Flea beetles and whiteflies, which may also be causing damage to the foliage, will likewise be exposed to their predators.

That may not offer much comfort if you’ve found that winter vegetables on your plot are especially troubled by birds. In that case, it’s worth putting up some new defences. 

I don’t think bird scarers really work: a pigeon will soon overcome its trepidation if the alternative is going hungry.

There are better ways to undermine the confidence of a bird. I tie string or old video tape to bamboo sticks surrounding the plants in a tight pattern that makes it hard for the bird to be sure it will be able to escape in a hurry should a cat or sparrowhawk suddenly appear.