Garden cleanup tips for preserving wildlife habitat

By Kerry Lewis

Spring comes late in Maine…very late, especially to those of us who are eager to get out in the garden. I’ve always tried to follow the soil health advice like avoiding compaction by not walking on the lawn and in garden beds while they are still saturated from snow melt and heavy spring rains. But recently, I’ve also been learning more about how to preserve habitat.

When planning our spring cleanups—especially in Maine’s cold, slow-to-wake spring—we should take into account insects that spend the winter here. Don’t rush to clean up the fallen leaves in garden beds, which provide sheltering habitat for overwintering butterflies, moths, bees and beetles.

LIGHTLY RAKE PATHS AND EDGES ONLY AS NEEDED to create a tidy appearance, leaving leaf litter under shrubs and perennials as natural mulch.
LEAVE LOW AREAS UNDISTURBED FOR AS LONG AS POSSIBLE.
DON’T REMOVE WINTER MULCH TOO EARLY as late cold snaps are all too common in our climate, and the mulch provides valuable insulation during the late winter/early spring freeze-and-thaw cycle.

When daytime temperatures are consistently above 50 degrees, remove mulch gradually; pull away from the base of the plants.

Brush piles and fallen wood also provide shelter for ground-nesting birds, salamanders and snakes and small mammals such as foxes, rabbits, chipmunks and shrews, and should be left until late spring (or permanently).

I leave much of the cutting back of perennials and grasses until spring, enjoying the stark beauty of the dried seedheads and stems through our long winter. These same hollow stems and seedheads provide winter homes for insects. Delay cutting back perennials until late spring, when you see new growth at the base, and don’t cut back everything at once. Stagger the cutting over the course of a few weeks to be sure insects have refuge somewhere in your garden. Leave 8 to 12 inches of stem instead of cutting stems flush to the ground. Do not prune spring flowering shrubs such as serviceberry (Amelanchier), blueberry, lilac, forsythia, viburnum and some hydrangea until after they bloom. These plants bloom on old wood (setting flower buds the previous summer/fall) and you will lose the beauty of the blooms while the insects miss the nectar. Summer flowering shrubs such as ninebark (Physocarpus), panicle hydrangea and sweet fern (Comptonia) can be pruned in early spring as they set buds on new wood.

Resist applications of pesticides or herbicides that can kill beneficial insects, particularly early in the season. Even organic sprays can harm emerging pollinators. Pull out problem weeds by hand instead of applying preventative treatments. When it comes to native plants that have evolved to tolerate Maine soils, no synthetic fertilizer is needed. An application of compost is enough to encourage strong growth and the production of flowers. Lightly mulch with leaf mold or pine needles.

Ultimately, spring gardening in Maine is an exercise in patience. The proper timing of spring cleanup tasks will ensure that the plants you have carefully selected to create a wildlife habitat will provide the best value to the beneficial insects you are intent on attracting to your garden.