We’ve written in recent newsletters about the value of cutting back peony and iris foliage which may harbor pests and diseases, and raking leaves is a fall tradition. But as you’re preparing your yard for winter, don’t forget that many beneficial insects will need places to overwinter. As Justin Wheeler of the Xerces Society explains, many native bees use hollow stems of dead plants as winter shelter, and some butterflies like the eastern black swallowtail spend the winter as a pupa attached to stalks or twigs, so clearing too much plant matter can reduce their numbers. Many species of native bees need open (unmulched), untilled ground in which to build their nests. Bumblebees queens, on the other hand, burrow into leaf litter and loose soil beneath it for the winter, and fritillary butterflies use leaf litter to shelter their larvae waiting for violets to emerge in the spring. He suggests that we “provide safe havens by setting aside undisturbed patches of habitat allowing leaf litter, standing dead twigs/stems, or other ground cover to remain. ‘Wild’, unmanicured locations will provide the protected nooks and crannies that pollinators and other animals need for survival.”
You’ll find more information in his excellent blog article.