Cut back perennials in fall, or wait for spring?
Wait. Healthy stems and seed heads stay up all winter and come down in early spring. Only diseased plants are cut now.
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Plant by plant, this fall.
Black-eyed Susan: leave it.
Maryland's state flower keeps its dark seed heads up all winter, and goldfinches feed on them.
Ornamental grasses: leave them.
Standing clumps shelter birds, and the insects that eat garden pests, through the cold.
Anything diseased: cut it now.
Mildew or leaf spots this year? Cut the stems to about 2 inches once frost has killed them, and bag the debris.
Should you cut back perennials in the fall or in the spring?
Spring, for healthy plants. University of Maryland Extension says to leave perennials and ornamental grasses standing through winter, then cut them in early spring, before days hold above 50 degrees and bees start flying, leaving 8 to 24 inches of stem. Only diseased plants come down in fall. Spring and fall cleanups are part of our landscape maintenance.
Sources: University of Maryland Extension and the Xerces Society. Checked on 11 October 2026.
The spring cut
8 to 24 in
of stem can stay standing after the cut, as nesting tubes for native bees that do not sting.
- 50°F steady by day is when insects wake and the cutting window closes.
- 1 inch of mulch or fallen leaves can go round perennials once frost has arrived, never over the crown.
Questions about cutting back
When do bees start flying in spring in Maryland?
Once daytime temperatures hold above 50 degrees, University of Maryland Extension says, because that is the warmth their flight muscles need. The spring cut should be done before then, so the hollow stubs are standing when bees come looking for nesting sites.
Which perennials should I leave standing for the birds?
Coneflower, Joe-pye weed, beebalm, mountain-mint and black-eyed Susan. University of Maryland Extension says their seed heads are both attractive in winter and a good food source for birds, and counts them among the exceptions to deadheading after bloom.
What should I do with perennials that had powdery mildew?
Cut them back in fall once frost has killed the stems, rake out the dead leaves and prune the stems to about 2 inches above the crown. Put the debris out for yard waste collection or in the trash: home compost rarely holds 131 degrees for three days, which is what it takes to kill the fungus.
Is black-eyed Susan an annual or a perennial?
A short-lived perennial, and sometimes an annual or a biennial. The common Maryland form is Rudbeckia hirta var. pulcherrima, found statewide on roadsides and old fields, blooming June to October. Its seed feeds songbirds, goldfinches above all, which is one reason to leave the heads standing.
Can the cut stems stay in the yard?
Yes. University of Maryland Extension suggests gathering trimmings into a pile and leaving them outside rather than disposing of them, so overwintering bees and other insects inside can still emerge in spring. Praying mantis egg cases are often fixed to stems too, and are left outdoors to hatch.
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Spring and fall cleanups, by themselves or with regular care, around Annapolis and on Kent Island. Tell us about the beds.
