Can Boxwood Hedges Be 5 Inches Wide?

Proper Trimming

• Boxwoods should be pruned lightly to remove sickly or dead stems, especially since their dense limb system often shades foliage from sunlight exposure. In general, prune your boxwood into a tapered shape. For example, a 36-inch wide base with a 24-inch wide peak provides good anchorage in the ground. In fact, this pruning technique also allows ample sunlight into the hedge for maximum photosynthesis. Leaves that typically would be shaded are open to energy production for strong plant growth.

Severe Pruning Repercussions

• Cutting your boxwood to 5 inches wide often removes most of the foliage; your hedge cannot survive without photosynthesis activity. Severe pruning often encourages pathogen or pest problems as well, because the boxwood is not strong enough to resist moderate environmental stress. Constant shearing causes limbs to grow even more densely to compensate for the exterior leaf loss, creating a thick canopy that does not allow healthy air flow through the hedge. Stunted growth and dieback occur with consistent severe pruning. Reverting to light pruning may rejuvenate the hedge.

Timing

• Most boxwood species have a flush of new growth come early spring as warming temperatures and longer days encourage rapid photosynthesis activity. Generally, allow your boxwood to grow new foliage until late spring or early summer. Once hot summer weather arrives, boxwood growth subsides. Prune your boxwood in late summer. For an informal appearance, prune your hedge only once. If you want a more formal look, cut the hedge lightly every 4 weeks until cool fall weather sets in. Winter weather does not encourage growth so your boxwood should remain well-formed until spring arrives.

Bonsai Specimen Exception

• The Japanese kingsville boxwood (Buxus microphylla "Compacta") is hardy in outdoor USDA zones 6 through 8 and only grows to a 12-inch height. This tiny boxwood species can be maintained in a 5-inch wide shape because it often is used in bonsai. Trained by professionals, a "Compacta" boxwood typically is purchased as a small specimen requiring only light pruning to retain the desired shape. Because it grows slowly, you should never need to prune it severely. Consistent care allows your bonsai to grow strong and healthy without much cutting involved.