As perennials die back, cut the foliage close to the ground. Insects-especially slugs- find the dead foliage to be a great wintering over or egg laying spot! Take the foliage away and you can really make a dent in the population of insects next spring.
Likewise, remove fallen leaves from shrubs and trees. These can harbor not only insects, but disease spores that can reinfect the plant next spring. If you know the leaves are infected, bag them up for the landfill. If the plant appeared healthy, you can put them in the compost pile. Now that you’ve removed the dead foliage from the ground, it’s time to recover the ground!
Mulch perennials with straw (hay contains seed), keeping it an inch from the trunks of trees and shrubs. If mulch touches the wood, it’s easy for rodents to hide in it and eat the bark. Why is it okay to mulch with straw, when you’ve taken away naturally occurring mulch?
Straw (a grass) generally isn’t a host for diseases and insects that infect shrubs and herbaceous perennials. One thing that most people don’t realize about winter mulching is that it shouldn’t be done until after the ground freezes.
This keeps the ground frozen for the winter- alternate freezing and thawing can heave plants, especially newly planted ones, right out of the ground. The mulch also keeps the ground from going too far below the freezing point. Now you’re done for the winter and can relax!