Thinking about ‘cleaning up’ your garden for the winter? You might want to reconsider. You may be disturbing the winter homes of many of the creatures you enjoy seeing during the warmer months.
For example, butterflies may be present in our yards and gardens in some life cycle stage year-round. Except for species that migrate or live in more hospitable climates, butterflies will need to find a safe haven to survive the cold winter months in northern locations. Fortunately, providing winter butterfly habitat may be less work than you think.
Leaving leaf litter is one of the most beneficial things you can do, for both the plants in your garden and the critters that live there. Great Spangled Fritillaries and Baltimores are among the many butterfly species that spend the winter in or under this free, natural insulation and rich fertilizer. A mulch that’s automatically replenished by nature every year, leaf litter helps to minimize the need for watering your garden, while protecting soil from erosion, and controlling weeds. As the leaves gradually break down, they replenish the soil with essential nutrients plants need to survive and flourish. Leaf litter is the best, most cost effective mulch you can use for your plants, and provides important habitat for insects and birds.
Many perennials and grasses have lovely forms in winter, while providing food and shelter for insects, birds and other critters, so it’s best to leave them standing as much as possible. Pictured here are just a few of the many plants that provide visual interest in winter. Butterflies that use some of these as food plants will often spend the winter in leaf litter below them, or on the plant itself. Some skipper caterpillars may make a winter shelter in grass leaves, while overwintering Eastern-tailed Blue caterpillars may take refuge in a seed pod.
For those lucky enough to have a meadow, maintenance recommendations include mowing to a height of 12-16 inches in late winter, but it’s best not to mow more than a third of a site in a given year. Although some overwintering butterflies and other beneficial insects will be lost as a result of mowing, the height helps to minimize harm to those whose shelters are at ground level or just above. The timing offers winter food and cover for birds. Mowing only a partial site enables the area to be repopulated by residents from the unaffected portions of the meadow.
Brush piles, logs, standing dead trees, tree cavities and loose bark may also provide overwintering sites, so preserve or make these available if you can. Eastern Commas, Question Marks, and Mourning Cloaks are some of the last butterflies active in late fall, and the first to emerge in spring. They spend the winter as adults, and are among the species that may use these winter shelters. Butterflies that overwinter in other life cycle stages may also take refuge here.
Birds may visit some of these plants for their seeds, like the Chipping Sparrow pictured here, feeding on Indian Grass. Hungry foragers like Chickadees and Goldfinches are likely to visit the mints and coneflowers. Birds may also find and feed on insects sheltering among these plants, including some of the overwintering butterflies. But to make up for it, they will feed on insects that may otherwise parasitize the butterflies. So over all, birds help keep the insect population in a healthy balance.
I like the look of nature in winter. It’s fun to search for signs of critters, like a butterfly chrysalis attached to a tree or shrub branch. A few leaves of grass tied together with silk may be a winter haven for one of the skippers. With birds foraging for seeds, fruits or insects, that’s all I need to keep me interested. That’s a good thing, because the more we can leave their habitat in a natural state, the more good we will do for the insects and birds we enjoy so much.