Gardening would be a lot simpler if there were some magical day everything in the garden should be pruned and one standardized way to do it. There isn’t. Nature is gloriously diverse and it takes time to learn the needs of all the trees, shrubs, vines and perennials in a yard.
I wanted to share some guidelines for flowering shrubs. They fall into two general groups: those that flower on last season’s growth (these bloom in the spring) and those that flower from shoots produced this spring (these usually bloom after June).
To get maximum flower production, prune the spring bloomers such as azaleas and forsythias as soon as the flowers are done. That way these shrubs get plenty of time to produce new growth for next year. Prune the other group in late winter to promote lots of growth that spring.
Shrubs that bloom on last season’s growth (prune when flowering is finished):
Azelea and rhododendron
Early white spirea
Shrubs that bloom on the current season’s growth (wait to prune until late winter):
Japanese beauty bush
Hills of snow
Anthony Waterer spirea
Coralberry and snowberry
The lists of shrubs comes from the “Sustainable Gardening Master Gardener Handbook.”