Family: Hydrangaceae

From China and Japan, these four species of summer-flowering climbers are closely related to hydrangea. For cool areas only, they are sometimes more spectacular than the climbing Hydrangea species, H. anomala subsp. petiolaris, and are useful for covering pergolas, tree trunks and walls.

Species

S. hydrangeoides, Japanese hydrangea vine, from Japan and Korea, is a very vigorous plant, which climbs by means of aerial roots. It can reach to 10 m (33 ft) or more. The hairy, serrated, deep green leaves have red stalks, and the flattened flower heads, which are 25-30 cm (10-12 in) across, are made up of tiny, cream flowers that are surrounded by ornamental, cream bracts.

S. integrifolium is a native of China and also reaches heights of at least 10 m (33 ft). It has oval, deep green leaves, sometimes with finely toothed edges, and in summer produces 30 cm (12 in) wide heads of cream-white flowers, with large, cream bracts around the edge.

Cultivation

These climbers like a rich, moist loam with added manure or leaf mould. They will thrive in partial shade or hill sun. Plant in autumn or spring, mulch the root area, and train the plant as it grows onto the chosen support. Remove the spent blooms wherever possible, as well as dead or straggly branches. Propagate from cuttings from early to late summer. Layers of mature growth will also strike in about 12 months.

Climate

Zone 5 for S. hydrangeoides, although zone 7 is needed for S. integrifoliwn.