Learning to Love a Winter Garden
Driving down Phoenix Lake Road, I pass a stand of three-foot-tall yarrow, a nearly indestructible perennial with long-blooming, flat-topped flower clusters and feathery foliage. For months now, it has been brown and withered, “dead” as some might say. But I love it, and am grateful to the homeowners who display it. Birds relish the dried seed heads; and to my eye, there is a certain beauty in the structure and muted colors of many hardy perennials in fall and winter.
So, I have mostly chucked the gardening aesthetic that says anything that looks dead should be immediately whacked to the ground or pulled up. While there are some perennials that should be cut back in fall (more about that later), many are better left standing until spring. Here are some reasons why:
Food for the birds. Some of the loveliest yet toughest flowering perennials, such as coneflower, globe thistle and black-eyed Susan, offer dried seed heads birds love. The American beautyberry bush has gorgeous rosy-purple berries that hang in clusters well into snow season.
Winter plant protection. Dried flowers, leaves and stalks collect snow and other loose leaves that help insulate the plant’s crown, increasing its chances of surviving the winter. Another aspect of winter protection is that cutting back often stimulates new, tender growth that cannot withstand our winters; this dieback sometimes endangers the whole plant.
Wildlife shelter. Many butterflies overwinter in plant “debris,” and even birds can take cover under substantial overwintering perennials.
A flag for you. Ever forget where you planted a prized perennial the previous spring? A plant standing through winter becomes a reminder in spring. The other benefit of leaving the dormant plant as a marker is that you won’t inadvertently dig up a beloved perennial in a spring planting craze.
While many hardy perennials are indifferent to being cut back—they survive either way—there are some plants that prefer not to be cut back in fall. A few perennials that appreciate being left alone until spring are asters, butterfly bush and coral bells.
All of that said, there are perennials and situations that call for fall cutback. If a plant has diseased or insect-infested foliage, cut back and dispose of the leaves (but not in your compost pile). Plants with blackened foliage—often a sign of fungal disease—should be cut back in order to reduce the inoculum that can reinfest the plant next year.
If you have to cut back perennials because of disease or overwintering preference, or because you can’t be talked into seeing beautiful architecture in a dormant, snow-covered yarrow, here are a few tips. Wait until after the first or second hard frost, when most perennials begin to go dormant. Cut the entire plant back to within two to three inches of the ground, but no more. Many perennials form next year’s new growth at bud and shoot sites located just above the soil. Cutting too close to the ground might prevent the plant from reemerging in spring or summer. Whether for the sake of wildlife or a new appreciation for the beauty of dormant plants, think twice about cutting back perennials in your winter garden.
