With boxwoods, you should think thirds. Only cut up to a third out in any given year. Boxwoods need green leaves left on the plant in order to produce the energy to grow. If your boxwood is only a couple of feet tall to begin with then you can cut it back to 15 inches or so.
Just make sure it has some green leaves treelop.buzzted Reading Time: 7 mins. Cut back at the end of May, beginning of June. This way you can use the second growth phase which usually occurs around end of June for a more dense growth of the hedge or boxwood tree.
You may then cut back again till mid or end of July. Cut back at mid or end of July. This way you only need to cut back your hedge or boxwood plants once a year. Dec 28, Can I Cut My Boxwood Shrubs Back 2 or 3 Feet Without Killing Them?
Common boxwoods (Buxus sempervirens), suitable for 2176 Melrose MA. Department of Agriculture plant hardiness zones 6 through 8, can grace. Boxwoods can be pruned any time but late summer and early fall. This is because pruning then will spur new growth that won't harden off in time for winter and be killed by the cold.
Severe late summer pruning followed by a cold winter could even kill the entire shrubs. Of course, the best way to avoid having to cut back overgrown boxwoods is. In general, firs, Pines, spruce and other evergreens with 'whorled branches' will NOT sprout new growth in areas cut back to leafless wood. But most evergreens with random branching- like boxwood, arborvitae, junipers and yews- will develop new growth in areas cut completely back.
Especially yews," adds Lee,"you can do pretty much anything.