As we move further into fall, overnight frosts and freezes send our perennials to bed. But there is still much that can be done to prepare our garden beds and borders for their winter rest. As perennial foliage is affected by hard frosts or freezes you can, in most cases, cut it back. The benefit to cutting back your garden in fall, is that you will be all set and ready to “grow” when spring finally does return to us. Getting your perennials all tucked in for winter with some fresh mulch will make all the difference in your spring work load out in the garden. There are a few exceptions to fall cut back that we should mention… Semi-evergreen and evergreen perennials such as, heuchera or coral bells, heucherella, helleborus or lenton rose, ajuga, ground cover sedums, and creeping phlox are popular examples of perennials that should NOT be cut back before spring has melted winter away. Any damage that these plants have sustained over winter can be carefully pruned out.
Ornamental grasses are another perennial that should be left standing for winter. Cut back your grasses in spring once our snows have melted. This prevents moisture from getting down into the crown of the grass clump, where repeated freezing and thawing could do serious damage.
That said there is no shame in putting off cutting back your perennials until spring. Leaving the dead foliage on the plants can help protect their root systems by catching leaves and fall debris. This is especially true of new perennials that aren’t fully established yet. If you do decide to wait until spring remember to get out there early to cut back. You don’t want your perennials new growth to be damaged. Whenever you cut back your perennials, keep in mind that diseased perennial foliage should be disposed of entirely and your pruner should be cleaned with a quick swish in some rubbing alcohol to avoid spreading disease from one plant to the next.
October is the time to get a few spring blooming bulbs in the ground. It’s the best time to dig and divide your peony clumps. Make sure you aren’t replanting your divided peonies too deeply. Two inches is ideal. Cool season crops like carrots, brussels sprouts, and squash can handle a few frosts but should be harvested before they are damaged by a hard freeze.