Mountain hydrangea is a small, 2 to 3 feet high shrub from the mountains of Korea and Japan with light pink, lace cap flower clusters in mid-summer. The slender green leaves often turn red or burgundy in autumn. It does well in part shade and is small enough to be used in containers. Marginally hardy in zone 5 and may be difficult to find in nurseries.
Size and form:
Mountain hydrangea grows 3 to 4 feet high and wide in a mounded form.
Native geographic location and habitat:
It is native to mountain areas in Japan.
Leaf or needle arrangement, size, shape, and texture:
Mountain hydrangea has simple, opposite, oval leaves that are 2 to 6 inches long with a finely toothed margin. Leaves are dark green in summer and have a slight red coloration in fall, which is better on some cultivars than on others.
Flower arrangement, shape, and size:
The small flowers appear in a lacecap arrangement. The flowers will be pink in alkaline soil and blue in acid soil. Some cultivars have white or pale blue flowers.
Fruit, cone, nut, and seed descriptions:
The dry capsule is not ornamentally important, but the remains of the dry flower heads that surround them provide winter interest.
Mountain hydrangea needs moist, well-drained soil that is high in organic matter. This shrub grows best in part shade. It flowers on old wood and therefore flower buds are vulnerable to harsh winters. Mountain hydrangea benefits from winter protection in colder climates and may not be fully hardy in zone 5. Plants may be difficult to find in the nursery trade.
Blue Bird Mountain hydrangea (Hydrangea serrata ‘Blue Bird’):
This shrub has bluish-pink lacecap flower clusters in alkaline soil that become more blue in acid soil. The coarsely toothed, dark green leaves are 8 inches long and turn reddish-bronze in fall.
Woodlander Mountain hydrangea (Hydrangea serrata ‘Woodlander’):
This cultivar has bluish-pink lacecap flower clusters in alkaline soil that become more blue in acid soil. It’s medium-green leaves have a purplish cast and turn purplish-red in the fall.
Preziosa hydrangea (Hydrangea ‘Preziosa’):
This hybrid grows 3 to 4 feet high and wide. It produces snowball-like flowers that start out white, turn pale green, tint pink, and mature through the season to an intense darker burgundy color. Leaves emerge tinted with purple and mature to green and then back to red and purple hues in the fall. Reddish stems add contrast to changing leaves.