One of the subjects I get asked about the most is how and when to prune trees and shrubs. Unfortunately the answer can be somewhat complicated. If you prune at the wrong time, you can cut off the buds that produce the flowers. A dependable and easy rule to follow is to prune spring-flowering shrubs and trees right after they finish blooming. Spring-flowering plants set their buds on “old wood” – last year’s wood – so pruning after they bloom will give them time to set new buds for next year. Never prune them in the fall or winter or you will cut off the flowering buds.
Another tried-and-true rule to follow – prune summer-flowering shrubs and trees in late winter. February is a good time. Summer-flowering plants set buds on “new wood” – new growth that begins in the spring, so winter pruning will not cut off any buds and will actually encourage more growth.
Some spring-flowering plants to prune right after blooming include: azalea, camellia, mophead hydrangea (Hydrangea macrophylla), oakleaf hydrangea, loropetalum, forsythia, and spirea.
Summer-blooming plants include: gardenia, PeeGee hydrangea (Hydrangea paniculata) (Annebelle and Limelight), butterfly bush (Buddleia), rose, abelia, crepe myrtle, and many pollinator perennials like sage, black-eyed Susan, coneflower.
Another rule of thumb: Trees and shrubs that do not flower are best pruned in late winter while they are dormant.
Why prune? Basically you want to prune a shrub or tree to enhance it health, for safety issues, and to control growth. Remember the four “D’s” when pruning. Remove dead, dying, diseased and damaged branches. Prune branches that cross each other or rub against another branch. Always prune back to the main stem at an angle, and clean and disinfect your tools often to avoid transferring any disease.
The UGA Extension office has many online publications regarding all aspects of pruning. For more information on pruning, go to extension.uga.edu/publications.
