As winter approaches the perennial garden’s vibrant hues fade and turn to shades of tan and brown. In the warm days of Indian summer the job of cutting back the summer bloomers can begin. As these become tired and worn looking each may be cut to the ground to let the fall bloomers shine. After two or three killing frosts have extinguished the bold colors of autumn, the job of tidying the beds for winter begins in earnest.
First, select the plants that will be left standing for interest through the winter. These may include ornamental grasses whose resilient stems will rustle in the winter winds and spring back amazingly even after being weighted down with snow or ice. Rusty brown flower stems of tall sedums stand proudly in the winter garden.
Leaving the dry seedheads of black-eyed susans and purple coneflowers will provide winter food for yellow and purple finches as well as slate gray juncos. On a frosty morning, these bright seed-eaters are lovely to see as they flit and alight on the stiff flower stems.
The bone white branches of Russian sage reach skyward waiting for the return of spring. Cut these back in spring after tiny new leaves can be seen, cut back to within 2-3 inches of the ground. This leaves a bit of stem that will be visible to locate the plants in spring when clearing leaves, removing mulch and fertilizing.
Generally garden debris can be added to the compost pile to enrich gardens to come. If however, the plant was in some way diseased or infested with insects it may be best to dispose of the dead material with your regular trash. Discarding this material reduces the possibility of repeat infections the following season. Foliage of irises especially should be removed from the garden to prevent borer infestations.
Many perennials form a rosette of leaves that lies nearly flat on the ground. The upright, flowering stems should be cut down leaving this basal rosette of foliage, which often will remain green all winter.
Many perennials are actually evergreen or partially evergreen and should be left standing in the winter garden. Candytuft (Iberis), rock roses (Helianthemum), and Lenten roses (Helleborus) are true evergreen plants.
Salvias, heucheras, some daylilies, low-growing sedums, some perennial geraniums and woodland phlox all remain at least partially green during the winter. Leave these to provide a bit of color in the winter garden. If care is taken to leave a variety of plants after the late fall chores are finished, the winter landscape will be filled with crystal-spangled stems, graceful bowing grasses and bright spots of green that promise spring’s arrival.
The winter garden need not be bare earth or simply a mulched bed. Add a few pansies, noted for their cold-tolerance, and you’ll be surprised to see spots of cheerful color on warm winter days and an early spring show that will last until nearly next summer.
After the ground freezes, usually after the winter holidays, a layer of mulch should be added to the garden to protect from repeated freezing and thawing that can cause frost heaving of plants.
Now that the beds are neat and ready for the wintry wind’s blast, the gardener has time to take stock of the garden that was and to imagine the garden that will be.
by Melodie Likel, Perennial Plant Specialist