In summer, Japanese hydrangea has white, flat-topped clusters of tiny flowers and single-petaled outer bracts. Blooms spread 8 to 10 inches wide against a backdrop of sharp-toothed, 6-inch-long leaves. Because its stems have aerial roots, Japanese hydrangea can cling to smooth vertical surfaces such as walls or tree trunks without additional support. It’s also attractive as a ground cover or draped over rock walls.
Common name: Japanese hydrangea vine
Botanical name: Schizophragma hydrangeoides
Plant type: Deciduous, rootlet climbing vine
Height: 20 to 40 feet long, depending on cultivar
Zones: 6 to 9
- Sun: Sun to part shade
- Soil: Compost-rich, well-drained soil
- Moisture: Moderately moist
- Mulch: Add a 2-inch layer of mulch around new plantings to keep soil evenly moist.
- Fertilizer: None required.
- Pruning: In late winter or early spring, remove dead stems and trim to maintain desired size.
- ‘Brookside Little’ has smaller leaves than the species. Zones 6 to 8.
- ‘Moonlight’ has silvery blue-green leaves and white flowers, blooming six to eight weeks in summer. It likes dappled shade and grows 20 to 30 feet tall. Zones 6 to 9.
- ‘Roseum’ has light rose bracts and dark green foliage. Blooms July and August. Zones 6 to 9.
- Foliage is yellow in fall.
- In winter reddish-brown stems add seasonal interest.
- Japanese hydrangea is slow-growing when young, but grows faster as it matures.
- In warmer climates, the plant likes some afternoon shade to help keep roots cool, but it tolerates hot, wet summers.
- Flowers best in full sun.
- Some sources list the vine as hardy to Zone 5.
- Infrequent insects or disease problems
- Cut greenwood cuttings in early summer.
- Cut semi-ripe cuttings later in summer.
All in the family
Mock orange (Philadelphus spp.), Hydrangea spp., and Deutzia spp. are some of the more familiar plants in the Hydrangeaceae family. Some less-known plants are wood-vamp (Decumaria spp.), waxflower (Jamesia americana), and Carpenteria californica.
Text by Mary Pestel, photo courtesy of Missouri Botanical Garden PlantFinder.