Before winter, remove all diseased debris and broken branches from your flower garden. Discard any remaining annuals.
Recommended perennials to cut back in fall are: bearded iris; monarda (bee balm) unless it is new growth; gaillardia (blanket flower); nepeta (catmint); columbine; daylily (now or spring); bush clematis; helianthus; hollyhock; ligularia (now or spring); penstemon; peony; and helianthus.
These perennials are recommended to leave for spring cutting: asclepias (butterfly weed); chrysanthemums (mammoth mums); and heuchera (coral bells).
Birds will appreciate it if you leave echinacea (cone flowers) and rudbeckia (black-eye Susans) or any other seed producing plants standing through winter.