Avoid late summer fertilization, because it can stimulate growth which is susceptible to frost or cold damage. Prune to remove diseased, injured, dying, or dead branches. Pruning can be done to shape plants and increase density any time of the year except six weeks before the average date of the first frost in the fall. As plants age, some of the oldest branches may need to be removed to allow light to reach the inner shoots. Continuous shading of the inner shoots results in foliage drop from those shoots.
Most boxwoods are slow to respond to severe pruning.
If severe pruning must be undertaken, do so in late winter to early spring. It may take the plant years to recover. A regular program of light to moderate pruning is preferred. Popular Selections Three species comprise most of the boxwoods planted in the United States. However, more than 160 registered boxwood cultivars exist.