Culture
Easily grown in average, medium moisture, well-drained soil in full sun to part shade. Tolerates full sun best if grown with consistently moist soils. Intolerant of drought, with foliage tending to decline considerably in dry conditions.
Noteworthy Characteristics
Hydrangea heteromalla, commonly known as woolly hydrangea, Himalayan hydrangea or Chinese hydrangea, is an upright deciduous shrub or small tree. It typically grows to 8-15’ tall in U.S. gardens, but occasionally to as much as 30’ tall in the wild in its native habitat which consists primarily of alpine forests and thickets in the Himalayas and China. Young branchlets are hairy. Ovate to elliptic leaves (to 8” long and 3” wide) with slightly serrate margins are medium green above but glabrous to white tomentose beneath. Leaves have showy red petioles. Flowers bloom in late spring to early summer in flat-topped corymbs (6-12” across). Each corymb features a few showy white sterile flowers (each to 1-2” across) which have 3-5 overlapping white petal-like sepals. The white sterile flowers eventually mature to pink or burgundy. Although the sterile flowers are few in number, they are arranged mostly along the periphery of the corymb surrounding numerous non-showy greenish-white fertile florets.
The genus name Hydrangea comes from hydor meaning "water" and aggeion meaning "vessel", in reference to the cup-like capsular fruit.
Specific epithet comes from Greek heteros meaning another or different and mallos meaning wool in reference to the tomentose leaves.
Problems
No serious insect or disease problems. Many species of hydrangea, including this one, are susceptible to bud blight, bacterial wilt, leaf spots, mold, rust and powdery mildew. Watch for aphids, mites, scale and nematodes.
Uses
Infrequently grown in American gardens.