The cool, sunny days of fall are a great time to do a little tidying up in your garden, raking leaves and removing dead annuals and fallen foliage from around your perennials. “One reason to clean up is aesthetics, but you also should remove dead perennial foliage that could harbor diseases that can survive the winter and affect next year’s growth,” says Darren Barshaw, product representative for Darwin Perennials, a perennial plant breeder and producer. “Wait to clean up until after a hard frost or two, when the sugars of the plant have gone into the roots and crown of the plant to prepare it to re-emerge in spring.”
But before you start cutting down everything in sight, some perennials benefit by not being cut back in fall. Keeping their foliage intact provides winter protection for the crown of the plant, which is where the stems join the roots, for a healthy start next year. Many perennials also provide winter food and shelter for birds and beneficial pollinators, so they should remain in place in your garden until next spring, says Barshaw.
If you’re not sure what you have, whether annual or perennial, wait until spring to remove dead foliage. It’s always better to be safe than sorry! It’s OK to wait until next spring altogether; most plants will be just fine without a fall pruning. Finally, don’t be too hasty to rip out perennials that seem dead next spring. Depending on the weather, some perennials may not make an appearance until late May. If you don’t see any activity by mid-June, however, it’s safe to assume your perennial didn’t make it through the winter, says Barshaw. Dig it up, and plant something new!
Below, the most common perennials and when to cut them back.