Q: Should I cut back my perennials to prepare them for winter? If so, when?
A: Cutting back perennials in the fall can be confusing because there are different reasons to cut plants back or leave them standing. Perennials such as prickly pear cactus (Opuntia humifusa) and Adam’s needle (Yucca filamentosa) never require cutting back. Perennials such as black-eyed Susan (Rudbeckia) and false indigo (Baptisia)produce beautiful seedheads that look great for most of the winter. Vines like Clematis have beautiful seedheads; and others, such as climbing hydrangea (Hydrangea anomala petiolaris), have showy exfoliating bark. The seedheads and foliage of most ornamental grasses are attractive left uncut. Sometimes it is beneficial to leave perennials such as Chrysanthemum and Stachys uncut throughout the winter because the foliage insulates the crowns of the plant and offers more winter protection. Plants that attract migrating songbirds or that reseed, such as coneflower (Echinacea), should not be deadheaded and can remain standing for the winter. Many perennial plants should be cut back to the ground in the fall for sanitation reasons. All plants infected with fungal diseases, such as peony (Paeonia) should be cut back in the fall to prevent the overwintering of fungal spores. Please contact Plant Information Service at (847) 835-0972 regarding cutting back specific perennials in the fall.