How and When to Prune Boxwood Hedges

Shearing

• Though boxwoods are also pruned, the more commonly used method of boxwood pruning is referred to as shearing. This means the overall removal of new plant growth as soon as it appears. This is to maintain the original shape and form of the plants to help develop a more compact form. Avoid excessive shearing as this leads to a thick outer foliage shell that stops light from reaching the inner plant areas. Lack of light leads to gradual foliage drop. Prune about 10 percent of the plant growth in shearing.

Pruning

• Prune the boxwood plants to remove certain parts or selected branches that are injured, dead or diseased. Plant areas that are damaged by cold also require pruning. Pruning is also done to create a certain shape such as in the creating of topiaries and to keep plants to required height.

Thinning

• Boxwoods also need to be thinned annually to allow new growth within the canopy. The plants generally retain their foliage for three years, with the current year foliage completely covering the previous seasons' growth. This thick growth increases the potential of disease within the canopy. Thin shrubs by reaching 6 inches inside shrubs and pruning inner stems until the younger inner twigs are visible. After thinning, smaller voids are sometimes seen in the shrubs. This is normal and allows light to reach the inner portions of the plant and air to circulate.

Timing

• The recommended time to thin boxwoods is during early winter. The cut branches may be used in holiday floral arrangements. Shear boxwoods following every new flush of growth in spring and early and mid summer. Shearing in late summer is not recommended as this forces plant to produce new growth that is highly susceptible to fall and winter cold damage. Prune boxwoods during the above freezing temperatures of winter and early spring. Do not prune during late summer or fall.