If you’re looking to improve the health, vigor, and overall appearance of your landscape, pruning is one of the best things you can do. #1 – Trees and shrubs are dormant Many early spring flowering trees and shrubs begin to break out of dormancy in late February. Is it too late to prune landscape shrubs? It depends. What Happens if You Trim Spirea Too Late?. Here are 5 reasons why! I would wait if they have started to send out growth especially since certain species require different pruning time and methods. Ann asks, “When is the best time of year to trim tree limbs and cut back shrubs?”The best time to prune or trim trees and shrubs is during the late winter while they're dormant, but there are exceptions. I saw him walking his dog last week on a … Take my neighbor. Is it too late to trim the azaleas? Q: I am trimming the bushes in our yard. Here are a few different types of trees and the best time of year to trim a tree: Deciduous. On the contrary, winter is actually one of the best times to prune. Spirea shrubs produce some of the most brilliant blossoms across their numerous limbs. These fast-growing bushes … And here’s some great news: It’s not too late to prune your trees and shrubs! However, gardeners often miss the beautiful tree or shrub flower show because they pruned too early. These are the trees which shed their leaves each year. Summer pruning can tame overgrown shrubs, especially those that should’ve never been set out in small spots to begin with. Pruning too soon can harm your trees and shrubs.So, when it comes to fall pruning, procrastination is the way to go. Most deciduous trees should be pruned in late fall to winter, according to the Wisconsin Horticulture division of the Extension Service. -- Pam. Read on … Early spring flowering plants develop blooms on old wood (that is, they formed flower bud initials during the previous year’s growing season) and pruning them in winter removes these flower buds.