Boxwood is an excellent choice for edging beds or paths and can be grown in sun or moderate shade. It will grow in soils with a pH range of 5.0-7.5. Littleleaf boxwood (Buxus microphylla) and common boxwood (B. sempervirens) are widely available. Littleleaf boxwood has small medium-green leaves, which often turn a yellowish green in winter. Common boxwood has larger darker green leaves but is reliably hardy only into Zone 6. Korean boxwood (B. microphylla koreana) is an extremely hardy form of littleleaf boxwood. It can be grown in protected sites in Zone 4 and throughout Zone 5. Some hybrids have been selected for hardiness and good winter color. These include Chicagoland Green, Green Gem, 'Green Ice', 'Green Mountain', 'Green Mound', and Green Velvet. All are hardy in Zones 5-9.