A: The primary principle in pruning is to encourage renewal growth from the base of the plant. This is accomplished by removing the oldest growth, to open the center of the shrub, allowing more light and air into the plant.
It is best to prune your shrubs during the winter months of February and March. Renewal pruning during the winter is the preferred method for pruning shrubs because the plant is dormant. Decisions on which wood to leave and which to remove are easily made when leaves are not present. The structure of the shrub is also important when pruning and is easier to determine during the winter. For specific pruning information contact your local county extension office.