This can mean waiting until spring when growth begins again, or doing it in the fall before the first frost puts the plant into dormancy. While everyone agrees that August and September are when these plants set their spring buds, some people say prune while the others say no. The buds that produce the spring flowers are being formed now and any pruning will remove next spring's blooms. And even if you lose a few buds you produce a healthier bush by having pruned it. Fall is also the time to attend to boxwoods, but put away those sharp garden instruments.
Boxwoods produce outside growth.
You need to go to the interior and snap off branches, by hand, which have no foliage on the branch in the first six inches. It creates holes in the beginning, but it allows sunlight and air to penetrate and fill in those places. The riskiest part about pruning in September is that it can stimulate growth that will not be strong enough to survive the winter. Russell Stone, owner of Stone's Greenhouse Inc. on Hungary Road, says that in the fall, plants should be developing a good root system and not a good canopy. In order to stimulate fall root growth, Stone suggests fertilizer, but to be careful with its selection.