Green Mountain boxwood is a hybrid that combines the handsome dark green evergreen leaves of the common boxwood (Buxus sempervirens 'Suffruticosa') and the hardiness of Korean littleleaf boxwood. This evergreen shrub grows into a perfect narrow pyramid to a height of 12 feet with full sun to partial shade and is not fussy about soils. This variety is very hardy, with minor bronzing during harsh winters. It may be visited by boxwood psyllid, a tiny insect that causes new leaves to curl up. The problem is cosmetic, and no treatment is needed. Regular clipping will keep the shrubs manageable. If planted against a house, the side facing the wall will brown out. It belongs in a hedge or as a vertical accent plant and is resistant to deer.