Appearance

Growth form

A deciduous woody vine that clings with small aerial roots on its stems. It can climb 50 ft (15 m) or more, or sprawl as a ground cover.

Leaves

Opposite, broadly oval, 2–5 in (5.5–12 cm) long on long stalks, with a heart-shaped or squared-off base and finely toothed edges.

Flowers

Flat clusters 4–10 in (10–25 cm) across of tiny creamy flowers, edged by a few showy white sterile flowers with about four petal-like sepals. Blooms in early to midsummer.

Fruit

Small brown capsules with winged seeds ripen in fall.

Look-alikes

Where it lives

Typical habitats

• mountain forests
• cliffs

Range

Native to Japan, Korea's Jeju and Ulleung islands, Sakhalin, and the Kuril Islands. In the US it is grown as an ornamental.

Preferred conditions

In the wild it climbs trees and rock faces in moist mountain forests.

Growing it

Care

Hardy in USDA zones 4–8. It is slow to get going for the first few years, then grows well in sun or shade with steady moisture; it blooms best with more sun. Its small aerial roots cling to stone, masonry, and wood.

Connected species

Close relatives

• Hydrangea anomala

  Its close cousin from China and the Himalaya, usually with fewer stamens and less showy flowers; some treat climbing hydrangea as a subspecies of it.

Name and classification

About the name

Often sold as Hydrangea anomala subsp. petiolaris. Many botanists keep it as its own species, separate from H. anomala of China and the Himalaya, which usually has fewer stamens.

Varieties and forms

Gardeners also grow selections with yellow- or cream-edged leaves, such as 'Firefly', and the small-leaved 'Brookside Littleleaf', which suits small walls.

Conservation

IUCN Red List

NENot Evaluated·Not yet assessed