To cut back or not to cut back ... in the garden, that is

It's time to clean up the garden before it takes its long winter nap. Whether perennials are cut back now or left standing until spring is answered by a couple simple questions.

First, do the plants offer food or shelter to wildlife? Next, do they have ornamental qualities that give the garden winter interest? If your answer was affirmative to either of these questions, plants can remain in the garden until spring … most of time.

Perennials that were assaulted by insects or disease should be cut back to reduce the chance of recurrence next year. Bee balm, garden phlox, German iris and peonies are examples of perennials with foliage that should be removed from the garden. Do not compost dead leaves; they may harbor disease spores or overwintering insects.

Plants that reseed with abandon should also be cut back before they scatter their seeds across the garden. There is plenty to do in the spring without adding the removal of multitudes of unwanted seedlings to the garden wake-up checklist.

Perennials that are too weak-stemmed to stand up to a little snow are not my idea of winter interest. Cut them back before they turn to mush unless the perennials are tender and use their withered leaves as a blanket.

After these perennials have been cut back, consider the rest. There are many perennials that provide food for birds and other wildlife in the winter. Birds love the seed heads of black-eyed Susan and coneflowers. A variety of butterflies and beneficial insects overwinter on native plants and juncos find refuge in dense garden cover.

Interesting seed heads can also make the garden attractive, especially when they are dusted with snow. Astilbe, coneflowers, Joe-Pye weed, sedum and yarrow are a few examples. The fawn-colored foliage of tall ornamental grasses adds vertical form to the winter landscape.

Perennials such as anise hyssop, asters, chrysanthemums, lavender and Russian sage benefit from the extra protection provided by leaving their foliage standing. Wait to tidy the semi-evergreen leaves of coral bells, dianthus, ferns, foamflowers and hellebores until spring, too.

Some gardeners prefer the look of a blank slate. They head to the garden, with pruners in hand, and don't stop cutting until the landscape is clean. Sometimes, to prune or not to prune is more a question of time than philosophy or aesthetic sensibilities.

I garden on an acre (and more than half is in beds and borders) and don't have time to cut back all the perennials in spring or in fall. Instead, after leaving plants with wildlife-value and a few of my favorites for winter interest, I cut back all the perennials in the front yard in the fall, so it is ready to show off spring-blooming bulbs.

Then I head to the back and cut back only those perennials that suffered from disease or insect damage and a couple self-seeding offenders. I leave the rest for cleaning up in the spring.

• Diana Stoll is a horticulturist, garden writer and speaker. She blogs at gardenwithdiana.com.