Buxus Sempervirens--commonly called boxwood--is a dense shrub with dark evergreen foliage that grows on a multibranch form. Its slow growth, fine texture and compact appearance make boxwood ideal for use in screens and privacy hedges, as well as in formal gardens and along walkways. Boxwood's tiny yellow flowers emit a distinctive, somewhat bitter odour. Boxwood tolerates pruning well and can be trained into a variety of hedges and shapes.
Prune your boxwood in mid to late summer for size by cutting back overly long stems so that the cut is within the shrub. Boxwood--if not otherwise shaped--grows by itself into a pleasing globular form.
Prune your boxwood for shape by removing the ends of the growing tips. Be careful not to cut too much; boxwood grows very slowly.
Perform a rejuvenation pruning on your boxwood every few years, preferably in April. Cut 1/3 of the living stems right back to the ground. The boxwood should respond the following season with a burst of vigorous growth.
Perform only minimal trimming until the hedge has grown to the desired height.
Once the plants are close to the optimal height for the hedge, cut the tops back to just a few inches below the preferred level. Do this in mid-summer.
Trim your boxwood hedge to shape in August or September.
Thin out growing shoots in early winter to open up the hedge to increased sunlight and air circulation. Using a sharp bypass pruner, reach inside the boxwood about 6 inches and prune off the stem. Continue thinning until you can just see the small interior twigs. According to the United States National Arboretum website, you should remove about 10 per cent of the outer branches to thin the shrubs successfully. After thinning, the remaining branches will spread to cover the gaps, and the entire hedge will benefit.
Prune your boxwood hedge in the spring or summer for diseased and dead branches, as well as any that are crossed.
Some people find the fragrance of the boxwood unpleasant, while others find it intoxicating. If your family includes some of the former, don't plant boxwood too close to a window or patio.