Culture
Best grown in average, medium moisture, well-drained soil in full sun to part shade. Prefers sun-dappled part shade and moist, sandy loams with a slightly acidic to slightly alkaline pH. Tolerant of pruning and shearing. Avoid cultivating around plants because they have shallow roots. Roots appreciate a good mulch (1-2 "). Thin plants and remove dead/damaged branches annually to improve air circulation. In USDA Zone 5, this boxwood is best sited in a sheltered location which protects it in winter from strong winds and full sun. Among the various types of boxwoods, Korean boxwoods are generally noted for having the best winter hardiness and are good selections for the St. Louis area.
Noteworthy Characteristics
Buxus sinica var. insularis, commonly called Korean littleleaf boxwood, is a dense, compact, many-branched, broad, mounded evergreen shrub with a loose and open habit. A slow grower (to 1.5" per year) which is typically grown as a 2-2.5' tall shrub with a larger spread, but which can reach 5' tall after 25 years if not pruned lower. An extremely hardy variety that is a good choice for northern climates. Apetalous, greenish yellow flowers (separate male and female flowers on the same plant) appear in spring. Flowers are sparse and insignificant, but quite fragrant. Small, ovate, light yellowish green to medium green leaves (to 3/4" long). Formerly known as and sometimes still sold as Buxus microphylla var. koreana.
Genus name comes from the Latin name for plants in this genus.
Specific epithet means Chinese.
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.
‘Winter Gem’ is a Korean boxwood that typically matures to 2-3’ tall and as wide. Synonymous with and sometimes sold in commerce as Buxus microphylla var. japonica ‘Winter Gem’ or Buxus microphylla var. koreana ‘Winter Gem.’
Problems
Boxwood foliage tends to bronze (turn unattractive brownish-yellow) in harsh winters, particularly if plants are located in open areas exposed to full sun and winter winds. Some susceptibility to blights and leaf spot. Root rot can also be a problem in poorly-drained soils. Plants are susceptible to boxwood leafminer, boxwood mites, and box tree moth, but are usually not affected by boxwood psyllid.
‘Winter Gem’ is noted for its ability to retain good green foliage throughout winter.
Uses
Small hedge or mass as a ground cover. Also useful as specimens or in small groups in a variety of landscape applications including shrub borders or foundation plantings. Bonsai plant.