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.
This plant has some cultivated varieties. Go to list of cultivars.
- Deciduous (seasonally loses leaves)
- Mixed border,
- Small shrub (3-5 feet),
- Low-growing shrub (under 3 feet)
- Partial sun/shade (4-6 hrs light daily),
- Full shade (4 hrs or less of light daily)
- Zone 5 (Chicago),
- Zone 6,
- Zone 7,
- Zone 8,
- Zone 9
- Acid soil,
- Moist, well-drained soil
- Mid summer,
- Late summer,
- Early fall,
- Mid fall
Size and Form
3 to 4 feet high and wide, mounded form.
Tree & Plant Care
Needs moist, well-drained soil, high in organic matter.
Best in part shade.
Flowers on old wood, so flower buds are vulnerable to harsh winters.
Benefits from winter protection in colder climates (may not be fully hardy in zone 5).
Plants may be difficult to find in the nursery trade.
Disease, pests and problems
No serious problems.
Native geographic location and habitat
Native to mountain areas in Japan.
Leaf or needle arrangement, size, shape, and texture
Simple, opposite, oval leaves; 2 to 6 inches long with a finely toothed margin.
Dark green in summer; some red coloration in fall (better on some cultivars).
Flower arrangement, shape, and size
Small flowers in a lacecap arrangement; 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 do provide winter interest.
Cultivars and their differences
Blue Bird (Hydrangea serrata 'Blue Bird'): Bluish-pink lacecap flower clusters in alkaline soil, becoming more blue in acid soil; coarsely toothed, dark green, 8 inch long leaves turn reddish-bronze in fall.
Woodlander (Hydrangea serrata 'Woodlander'): Bluish-pink lacecap flower clusters in alkaline soil, becoming more blue in acid soil; medium-green leaves, with a purplish cast, turning purplish-red in the fall.
Preziosa (Hydrangea 'Preziosa'): 3 to 4 feet high and wide; snowball-like flowers begin white to pale green, then 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.