Unless you want to leave seedheads in place for winter bird feasting, it’s a good idea to jump-start spring clean-up by pruning perennial stems before the snow flies. Don’t cut stems of plants like Russian sage (shown) shorter than 2 feet, especially in coldest areas. Shortening stem height helps protect plants from heavy snow. In coldest regions, avoid snipping stems shorter than about 4 inches. Remaining stem stubs catch fall leaves, which can help insulate plant crowns.