Flowering shrubs and branches need pruning for three reasons: to ensure plant health, to promote the growth of new flowering branches and to control size or shape. Shrubs that are not pruned will bear fewer blooms and may bloom only on high branches, negatively impacting the plant's aesthetic appearance. Improper or out-of-season pruning can damage your flowering shrub and reduce the number of flowers.
Wait for frost danger to pass to prune your flowering shrubs. If your shrubs flower in early spring (like lilacs or flowering quince) delay pruning until after the shrub blooms; shrubs that bloom in summer can be pruned whenever frost danger passes.
Inspect the branches for signs of dead, diseased or damaged wood. Dead wood feels hollow to the touch and does not move in the wind. Diseased or damaged wood bears wounds or scars and may be discolored or broken. This wood needs to be removed for the health of your shrub.
Clip off dead, diseased and damaged wood at its base. Between cuts, spray your pruning tools with disinfectant to avoid spreading disease between branches.
Remove up to one-third of the old branches to promote the growth of new ones, since flowering shrubs and branches need a supply of new wood. This thins out the shrub's interior to increase air circulation, which keeps shrubs healthier.
Trim back the tips of long branches using anvil pruners. Work one branch at a time, cutting back to a lateral branch or a node. Make your cuts at a 45 degree angle, not flat across.