If you prune shrubs and trees now, it will provide several benefits over pruning during the growing season, according to Kunso Kim, head of collections and curator.
Without leaves, “you are able to see the shape of trees and shrubs,” Kim says, though evergreens can be pruned in late winter too. Pruning now will guide the plant’s development when it resumes normal growth in the spring.
When it’s cold, the pruning process is less likely to spread disease-causing fungal spores or bacteria, or the eggs of insects, from one plant to another. And the wounds you make by cutting off branches won’t remain open very long before the plant starts growing and safely seals them over.
The benefits of dormant pruning hold true for trees as well as shrubs, although you will need to call in a professional arborist to prune or remove a major tree.
When a tree crew is working in your garden in late winter, the fact that the soil is frozen and can’t be compressed by foot traffic and equipment is good protection for perennials and the roots of trees.