Buxus microphylla

Littleleaf boxwood (Buxus microphylla, Buxaceae) is a slow-growing broadleaf evergreen shrub from Japan and Taiwan, typically 1 to 3 meters tall with a compact, rounded form. Small oval leaves (10 to 25 millimeters long) with rounded or notched tips are bright green, denser and finer-textured than those of common boxwood (B. sempervirens). Bark is grayish-white to pale brown. Inconspicuous green flowers appear in April to May. Foliage may bronze or turn orangish-brown in extreme cold or full sun exposure.

Littleleaf boxwood grows in sun to part shade on moist, well-drained loams across a broad pH range (4.5 to 8.5), hardy in Zones 6a to 10b. Shallow roots benefit from mulching. It is resistant to rabbit and deer browse and becomes reasonably drought tolerant once established. Disease pressure is notable: documented associations include boxwood blight, Phytophthora root rot, Volutella leaf and stem blight, leaf spot, canker, and black root rot. Pest associations include boxwood leafminer, boxwood mite, boxwood psyllid, and scale insects. Cultivars include 'Winter Gem,' 'Wintergreen,' 'Gregem,' 'Golden Triumph,' and 'Compacta' (Kingsville Dwarf, a miniature form suited to bonsai).