Boxwood (Buxus spp.) Hedges fit formal gardens and historical gardens well, but variegated box is fine for casual landscapes, too. Common boxwood (Buxus sempervirens “Variegata”), hardy in U.S. Department of Agriculture plant hardiness zones 6 through 8, and Japanese boxwood (Buxus macrophylla var. Japonica “Variegata”), hardy in USDA zones 3 through 10, both contain variegated cultivars. Keeping naturally shrubby boxwood thick and appealing depends upon location and regular pruning.
Plant fresh shrubs in part sun to protect against scorching, but pick a room with “open shade” — trim out tree branches if necessary to present bright or dappled shade. Choose a location with well-drained dirt and mulch with shredded bark or compost to keep the roots cool.
Fertilize the shrub with granular 10-6-4 fertilizer spread around the drip line over the mulch in late autumn beginning after its second year of development. Fertilizing too close to frosty weather promotes weak, leggy growth which will fall victim to winter kill and dieback. The higher nitrogen content promotes leaf development.
Prune variegated boxwood approximately six weeks before the last frost in your area to encourage vigorous lateral growth. Boxwood grows gradually, but annual trimming maintains it thick. Cut the lead tip of every branch back to a lateral branch or bud facing freezing to support shrubby growth.
Clean out diseased branches at any moment, but also cut two or three of the earliest divisions back to the ground with hand shears or a lopper every drop to admit light to the center of the bush. Repeat each drop — boxwood falls nesting inner leaves, so thinning the center of the shrub allows light in, which raises the visual appeal of fragile development by stimulating new development to replace aging leaves.
Shape shrubs when pruning, making the very best narrower than the base so that the underside gets a lot of light. Keep tops smaller compared to foundations to support growth around the base of the shrub.