I spent the early part of last weekend doing more fall cleanup, including cutting back some of my perennials. I thought it might be a good time to review which perennials you should NOT cut back in the fall.
Don’t cut back anything considered evergreen. Evergreen perennials include some primrose, coralbells, dead nettle, creeping phlox, pinks, spurge, hellebore, bugleweed, rock cress, sea thrift, wormwood, heart-leaf saxifrage, lungwort, barrenwort, saxifrage, creeping sedum, hens and chicks and thyme.
If you see a clump of green leaves at the base of spring and summer flowering plants, don’t cut these clumps back. These are rosettes and the plants will grow from these next spring. You’ll see rosettes on Oriental poppy, sage, foamflower, tickseed, and jacob’s ladder.
Of course, if your perennial has a nice fall and winter effect, like ornamental grasses do, feel free to just leave them until spring. Be sure to deadhead any flowers, though.
Some other perennials, like asters and joe pye weed provide seeds and habitats for wildlife over the winter, so you can leave those, too.
Your plants won’t die if you don’t cut them back, so don’t sweat this too much. Mostly, it depends on your schedule and whether you’re more likely to have time now or in spring for cutting them back. Personally, I do like to get rid of the ones with dead foliage that’s unattractive, like daylilies. Kind of cleans up the whole bed and, mentally, makes me prepared again for spring.