Nettles

We humans reserve a particular dislike for things that we think might hurt us: wasps, spiders, brambles, thorns and …. stinging nettles.

But for four of the five British butterflies that overwinter in their adult form, red admiral, peacock, small tortoiseshell and comma, common nettles (Urtica dioica) are their caterpillars’ main food plant.

If your No-Mow-May lawn has produced nettles, don’t panic. Check them for butterfly eggs or caterpillars and, if you find any, please consider a No-Mow-June as well.

The eggs of the comma butterfly, for instance, won’t take long to hatch, just four or five days, but the caterpillars will need four or five weeks, exclusively eating your nettles, to grow big enough to pupate. And a peacock caterpillar, after those four or five weeks, will attach itself to a nettle stem before pupating and becoming a chrysalis that will take a further twelve days to hatch into this year’s adult.

Just the month of May is not long enough for any of these four nettle-dependent species to complete their life cycle from egg to adult.