Elephant Hawk-moth cocoon hidden in fallen leaves

Winter is a harsh time for most insects in the UK, yet they've all evolved strategies to get them through a period when food is scarce and temperatures are too low for them to be active. Providing winter homes for insects is an easy way to get more butterflies and moths in our gardens in the summer months, and the good news is that it involves doing fewer jobs in the garden, so we have more time to enjoy it!

If we had a sixth sense that allowed us to see where these insects go in the winter, our gardens would look very different to us. In piles of leaves we would see hundreds of caterpillars and pupae tucked away from predators and the worst of the weather. Some, like the Elephant Hawk-moth, might have formed a silken cocoon and wrapped themselves in a kind of sleeping-bag made of leaves. Others are hunkered down as free caterpillars, waiting among the leaves until green growth comes back on the plants so they can resume feeding and go to the next stage in their life cycle.

Tiny moth patterns on a leaf

Some tiny moth species would even be living inside the leaves where they have tunnelled around, eating their way through and making beautiful patterns that we can easily see.

Others won't have got that far - they could be eggs that were stuck onto twigs by the adult moths in the autumn and won't hatch until the buds burst in spring.

Along tree trunks and twigs of shrubs we might see the pupae of butterflies like the Orange-tip. This butterfly flies in May and June and the caterpillars feed for just over a month before crawling off to find a hard surface above ground. There they tie themselves to it with a thin strand of silk and shed their skin to become a striking thorn-shaped pupa. This starts off bright green, but soon becomes pale brown, perfectly matching the woody plant material around it. Almost no predator would have a chance of detecting the nutritious meal inside, and it's not surprising that some gardeners aren't aware either.

Orange-tip butterfly Chrysalis on a twig
Orange-tip chrysalis on a twig

What looks like a lifeless twig or a pile of dead leaves could harbour the next generation of butterflies and moths that bring us such delight in the warmer months. So it feels like a tragedy to see piles of burning leaves and branches in gardens across the country, knowing that millions of insects are perishing this way and for no good reason other than the pursuit of a tidy garden.

A tidy garden might be able to support insects in the summer if it has flowers that are rich in nectar and pollen to feed the adults that are looking for this food to keep them going. But that's where the relationship between a tidy gardener and insect ends. Severely cutting back hedges to neat shapes, removing all long grass and the dead stems of plants, and clearing leaves from every corner of the garden might provide aesthetic satisfaction, but these actions sweep away the winter homes of insects.

Yes, as a gardener, I don't want complete chaos. The garden has to work for both gardeners and wildlife. So, I take a more relaxed approach.

Here are my top tips:

Go easy with hedge pruning

Leave some parts unpruned for a year or two, and do this on a rotational basis so that you can still maintain it as a hedge without wiping out entire generations of insects. Birds will also prefer this, as deeper hedges make better nesting sites for birds like wrens and blackbirds.

Leave the leaves

By all means remove them from lawns to keep the grass in good condition, but pile them in quiet corners of the garden or on flower beds. They will supress the growth of weeds while also adding nutrients to your soil. Various caterpillars live amongst leaves, while birds and hedgehogs will also feel more at home in your garden if they have places to snuffle and root around in.

Start habitat piles

This might be a pile of twigs and branches and leaves where things can retreat to in the winter months. Having more of these in different parts of the garden will help the caterpillars that don't move very far from their food plants.

Have some areas that are completely untouched

These might be around the edges or under trees so that you can still have a neat garden that is balanced by these wilder spaces.

 

The next question is what to do in spring. But that can wait for now - the less you can do in the garden between December and March, the better for insects. Tread lightly and take it all in. Go out on freezing days and look at the frost-gilded stems of plants that you've left. Think of the queen bees in their subterranean chambers, and the hefty Elephant Hawk-moths in their silken sleeping bags. Take a rest while the garden is resting, and make plans for new life in the months ahead.