Deb Babcock's gardening column appears Thursdays in Steamboat Today.
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If you haven't yet gotten out in the garden to clean up after our last good frost, now might be a good time to do so to avoid a huge, messy clean-up project next spring.
Frost-killed vegetable and annual plants should be pulled up and discarded in the compost heap. Clean up dropped leaves and limp foliage from your perennials, shrubs and trees, as insects and small animals tend to make nests and winter there. I had a family of mice or voles living among the roots of my spirea a couple winters ago, almost killing the shrub.
However, don't be too quick to cut all of your perennials to the ground. Some of the more unusual looking seedheads can give your garden character and interest through the winter. Plus, some shrubs and perennials actually benefit by leaving stems and leaves on through the winter. Butterfly Bush, Spirea and Russian Sage, for instance, use their stems to send energy to their roots and catch blowing snow, which acts as insulation and provides moisture.
In my garden, I don't cut down the tall grasses (Calamagrostis) since they tend to peek out above the snow to add some interest, and I leave seedheads from coneflowers and some sunflowers to provide a food source for birds. The rest of the perennials are cut down to 1 to 3 inches above the ground.
Pruning of shrubs is best left until late winter or early spring unless you have branches that could be damaged by fierce winter winds or a really heavy snowfall such as what we experienced last winter. The exception is rosebushes, except climbers, that can be cut back to 1 to 3 feet tall. Then, mound mulch or fresh topsoil, or cover with cones or baskets for the winter.
Each winter, many trees in the Steamboat area are damaged by sunscald. Anything that helps snow accumulate on exposed foliage to provide protection from sun and drying winds will lessen the chance that your trees will be affected.
Grass lawns should be aerated if your soil is compacted. Fall is the time to apply herbicides to control weed infestation and fertilizer designed for root development (slow-release nitrogen or high-phosphorus content).
A layer of loose mulch several inches thick around your plants, but a couple inches away from the main stem, helps your soil retain moisture while allowing oxygen to flow freely. This also keeps the soil temperature stable, avoiding the freeze and thaw cycle that is harmful to plants.
Finally, take time this fall to amend your plant beds by tilling or forking in a couple inches of rich compost into the soil. Next spring, your beds will be ready to plant as soon as weather permits.
Deb Babcock is a master gardener through the Colorado State University Cooperative Extension office in Routt County. Questions? Call 879-0825.