Culture
Best grown in evenly moist, well-drained loams (sand-clay mixture) in full sun to part shade. Plants will grow well in a variety of part-shade situations, including open sun-dappled conditions or light shade with several hours of morning sun or early afternoon sun. Plants can grow in close to full shade, but typically are less vigorous and more open with decreased foliage density. When grown in full sun, plant foliage is more likely to scorch, bronze in winter or suffer from mite attacks. Plants prefer soils with a pH of slightly acidic to slightly alkaline. Plants are generally tolerant of pruning and shearing as needed. Pruning should never be done prior to the last spring frost date. Pruning too early in spring often promotes tender new growth that may be damaged or killed by a late spring frost. Avoid cultivating around plants because they have shallow roots. Roots appreciate a good organic (e.g., bark or compost) mulch (1-2”). Thin plants and remove dead/damaged branches annually to improve air circulation. This boxwood is best sited in locations sheltered from strong winds and full day winter sun. Winter winds can remove moisture from leaves at a rapid rate, often resulting in dehydration and bronzing. Plants may be propagated by cuttings.
Noteworthy Characteristics
Buxus microphylla, commonly called littleleaf boxwood, is a slow-growing, densely-branched, broadleaf evergreen shrub. Most cultivars sold in commerce today mature over time to 3-4' tall. Tiny, rounded, leathery, elliptic to obovate, medium green leaves (1/3" to 1" long) with blunt tips are evergreen. Leaves may bronze in winter, but good green color usually returns by mid-spring. Axillary petalless fragrant spring flowers are inconspicuous.
Genus name comes from the Latin name for plants in this genus.
Specific epithet means small-leaved.
Common name of boxwood is in reference to the prior use of the wood to make boxes. Another theory on common name is that boxwood describes the quadrangular (square box cross section) stems of young plants.
'Compacta' is a dense, compact cultivar whose leaves often bronze in St. Louis winters. ‘Compacta’ is an extremely slow-growing cultivar that may reach only 8-10” tall in the first 15 years. Obovate, evergreen, light green leaves (to 1/4” long). Insignificant spring flowers. It is valued as a bonsai plant.
Problems
Boxwoods can be somewhat temperamental plants to grow in the St. Louis area where the evergreen foliage tends to bronze (turn unattractive brownish-yellow) in harsh winters, particularly if plants are located in open areas where exposed to full sun and winter winds. No serious insect or disease problems. Some susceptibility to blights and leaf spot. Root rot can also be a problem in poorly-drained soils. Plants are susceptible to boxwood leafminer and boxwood mites, but are usually not affected by boxwood psyllid.
Uses
Edging or rock garden plant. Accent for small areas. Bonsai.