It can spread from infected trees to healthy trees by sap-feeding beetles picnic bugs.
Prune these shrubs when they are dormant or in early spring before budbreak. If you postpone pruning until late spring or early summer, you will remove many flower buds.
Examples of summer-flowering shrubs are hydrangeas, roses, Japanese spirea, rose-of-Sharon, potentilla, and smokebush.
Do not prune branches back to older growth down the stem as new growth will not develop from these areas.
Wisconsin’s Ultimate Pruning Guide for Trees, Shrubs and Perennials. Check out this guide and pruning video at the bottom to become an expert on how and when to prune your plants. FRUIT TREES: All fruit trees: Late winter is best: and website in this browser for the next time I comment.
The best time to rejuvenate large, overgrown shrubs is late winter or early spring (March or early April). Heavy pruning in late winter or early spring will reduce or eliminate the flower display for 2 or 3 years.
However, rejuvenation pruning will restore the health of the shrubs.
The University of Wisconsin Extension provides educational materials on training and trimming these special trees to keep them productive.
Aug 13, In early summer, you can also remove 2∕3 of an unbranched tip to keep the tree fuller. Hemlocks, arborvitae, and yews: These evergreen trees and shrubs have latent (dormant) buds farther back down the stem. Therefore, you can shear these evergreens in late spring or early summer after new growth has expanded.
When is the best time to prune shrubs? The timing of pruning is different depending on what type of shrub it is and when it flowers (except for evergreens). For example, to preserve the flowers, lilacs should be pruned after flowering in early spring. Since their flower buds set over the winter on year-old wood, if they are pruned in the winter.