Get the timing right
In the Burtonsville area, which sits in USDA Hardiness Zone 7a, the first hard frost usually arrives between late October and early November. That frost is your signal to start, not the calendar. Cutting plants back too early, while they still have green leaves, removes energy the roots are still storing for next year. Wait until the foliage has yellowed and died back on its own.
Cut back the right plants, and leave the rest standing
Not every perennial should be cut down in fall. Cut back plants that are prone to disease or that turn mushy, including peonies, bearded iris, daylilies, hostas, and garden phlox. Trimming these to about 2 to 3 inches removes the spots where fungus and insect eggs overwinter.
Leave others standing through winter. Coneflower, black-eyed Susan, sedum, and ornamental grasses hold seed heads that feed goldfinches and other birds, and the stems mark where the plant is so you do not dig into it by mistake in spring. Standing stems also catch snow, which is one of the best insulators a garden bed can have. You can cut these back in early spring before new growth starts.
Divide spring bloomers now
Fall is the correct time to divide perennials that flower in spring and early summer, such as daylilies, hostas, and peonies. Dig the clump, split it into sections with healthy roots, and replant at the same depth. Plants that bloom in late summer and fall, like asters and mums, are better divided in spring so you do not disturb them right before dormancy. Get divisions in the ground at least four weeks before the first frost so roots can settle.
Feed the soil, then water
Work a one inch layer of compost into your beds. Over the winter it breaks down slowly, improves drainage in our heavy clay soils, and releases nutrients right as roots wake up in spring. Skip quick release fertilizer in late fall, since it pushes tender growth that frost will kill.
Keep watering until the ground freezes, especially anything planted this year and any broadleaf evergreens. Plants going into winter dry are far more likely to suffer cold damage than plants that are well hydrated.
Mulch after the ground cools
Wait until the soil has cooled and the first frosts have passed before mulching, usually mid to late November here. Mulching too early keeps the soil warm and tells plants to keep growing. Apply 2 to 3 inches of shredded bark, leaf mold, or straw, and keep it a couple of inches away from plant crowns so they do not rot. The goal is to keep the soil temperature steady, not warm. Freeze and thaw cycles in zone 7a are what heave shallow rooted perennials out of the ground, and a steady mulch layer prevents that.
Handle tender plants and shrubs
Dahlias, cannas, and elephant ears are not reliably hardy here. After the first frost blackens the foliage, lift the tubers, let them dry, and store them somewhere cool and dark. For broadleaf evergreens like azalea, rhododendron, and holly, a spray of anti desiccant in late fall reduces moisture loss during cold, windy stretches.
A simple fall order of operations
Wait for frost, cut back the disease prone plants, divide spring bloomers, topdress with compost, water deeply, and mulch once the ground has cooled. A few hours of work now is what gives you a full, healthy bed in spring instead of bare gaps and winter loss.
If you would rather hand off fall bed prep, Hometown Landscape handles seasonal maintenance and planting across Burtonsville and the surrounding Montgomery and Howard County communities.
For help with your own yard, explore our full range of landscaping services in Burtonsville, MD.