The techniques for pruning most broadleaf evergreens are similar to those for deciduous shrubs. Thin to reduce height and control size. Prune lightly just before flowering or more heavily right after, if the flowering effect is important.
Don’t use hedge shears to prune broadleaf evergreens that have large leaves. Cutting through the foliage disfigures it and results in an unsightly shrub. Broadleaf evergreens with fine-textured foliage — for example, boxwood or Japanese holly — can be sheared into a formal hedge without ill effect.
Rejuvenating Broadleaf Evergreen Shrubs
As with most other plants, broadleaf evergreens can grow too large for their landscape space. Regular thinning controls height and width. A leggy, overgrown shrub can usually be rejuvenated over several years by drastic pruning in late winter or early spring. Every year for three or four years cut back about one third of the oldest stems to the ground or thin tall stems back to lower side branches. This gradually reduces height and encourages new shoots to develop. Occasionally an entire plant can be rejuvenated in one step by cutting all the branches back to just above the ground and letting new branches emerge. This technique only works on healthy vigorous plants.