With boxwoods, you should think thirds.
As noted, they're fast growers says Lee, so to re-create four-foot high plants, cut them back to around three feet and then shear them a couple of times as they're growing throughout the season; this will promote a nice dense growth bushmulching.clubted Reading Time: 5 mins. Dec 28, Neglect regular pruning, though, and a wall of evergreen foliage soon looms over your garden.
Severe pruning of boxwoods can have mixed results, but you may be able to safely cut the shrubs back by Missing: Suwanee GA.