Look for branches that rub together or cross each other and remove the weaker of the two. The tree or shrub is now much better than when you began and you may decide to rest content with your labors. When to prune Dead, damaged and diseased wood can be removed at anytime. Diseased wood in particular should be removed as soon as it is discovered. Major pruning is best done just before a plant breaks dormancy and begins its period of rapid growth.
Timing is critical for pruning ornamental shrubs and is related to age and type of flowering wood.
Late summer and autumn flowering shrubs bloom on the current season' s growth. Prune these plants in the spring. Spring and early summer flowering shrubs bloom on the previous season's growth. Prune these plants after they flower. This allows new wood to grow and ripen before the plant blooms the following spring, Tools There are three basic pruning tools that should be in every gardener's potting shed.