Japanese hydrangea vine

Sun

Partial shade is ideal. Tolerates full shade with fewer flowers, or more sun where summers are cool and the soil stays moist; protect from hot afternoon sun.

Water

Keep evenly moist, especially during establishment and summer dry spells. Established plants tolerate brief dry periods but perform poorly in persistently dry soil.

Soil

Humus-rich, moist but well-drained soil, preferably slightly acidic to neutral. Avoid waterlogged ground and shallow, dry soil beside foundations.

Height

20-40 ft (6-12 m)

Spread

6-12 ft (1.8-3.6 m)

Flowers

Early to midsummer; flat clusters of tiny creamy-white flowers surrounded by showy, single white bracts.

Foliage

Broad, pointed, toothed green leaves on reddish-brown stems; leaves often turn yellow in autumn before falling.

Growth

Slow during its first few years, then moderate once established.

Care needed

Medium

• Pollinators
• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Fairly tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   2 ft (0.6 m)

2. After 1 year

   2.7 ft (0.83 m)

3. After 2 years

   3 ft (1.1 m)

4. After 3 years

   4 ft (1.3 m)

5. After 5 years

   6 ft (1.8 m)

About 5 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Growth rate

Slow

• Water deeply during dry weather for the first two or three growing seasons, keeping the root zone moist rather than saturated.
• Apply a 2-3 in (5-8 cm) mulch of leaf mould or compost each spring, leaving the stem base clear.
• Plant away from the driest strip beneath roof overhangs, and water the planting area rather than just the stem base.
• Tie young shoots to a sturdy support until their aerial rootlets attach; use sound masonry or a substantial trellis, not damaged mortar or painted timber.
• If growth is weak, apply a balanced fertiliser in spring at the label rate; avoid heavy feeding with nitrogen.

Pruning. Prune lightly just after flowering to shorten shoots that have outgrown their space, keeping growth clear of gutters and windows. Remove dead or damaged stems in late winter; heavy pruning can reduce subsequent flowering.

Late winter

Check supports and ties, and remove dead or damaged stems.

Spring

Plant when the ground is workable, water thoroughly, and mulch the root area.

Late spring

Guide new shoots onto their support and check moisture beside walls.

Summer

Water deeply during dry spells, particularly while the plant is establishing.

After flowering

Shorten unwanted shoots and clear growth from roofs, gutters and openings.

Autumn

Plant in mild regions while the soil is still warm, and water if autumn is dry.

• Cover a sturdy wall in partial shade with leafy growth and white summer flowers.
• Train over a substantial pergola or arbour where the flowering side shoots can hang freely.
• Use as a vertical backdrop to hostas, ferns and other woodland perennials.
• Grow against dark brick or timber on a separate trellis to make the white bracts stand out.

Garden styles it suits: Woodland, Japanese, English country, Romantic rose garden, White garden and Secret garden.

Plant it with: Hostas, Japanese painted ferns, Astilbes, Hellebores, Japanese forest grass and Rhododendrons.

Wildlife: The small fertile flowers attract visiting bees and other insects. Mature growth can provide shelter and nesting cover for birds.

• Little growth or few flowers in the early years: establishment is naturally slow; maintain moisture and avoid repeated moving or hard pruning.
• Scorched leaves or wilting: improve watering, mulch the roots and protect from strong afternoon sun and drying wind.
• Yellow leaves and weak growth in wet ground: check drainage and reduce watering; roots need moisture but not standing water.
• Shoots fail to attach or pull away: tie young stems to a secure framework and check that the supporting surface is sound.

Not known to be toxic to people, cats, dogs or horses, although species-specific poisoning information is limited. No particular plant part is established as hazardous; it is ornamental, not an edible plant.

• Climbing hydrangea (Hydrangea anomala subsp. petiolaris)

  Its showy sterile flowers usually have four broad sepals forming small flower-like units; Japanese hydrangea vine has a single conspicuous, teardrop-shaped white bract beside each outer sterile flower.

Schizophragma comes from Greek words meaning 'split partition', referring to the fruit capsule, while hydrangeoides means 'resembling a hydrangea'.

Propagation. Layer a low, flexible stem in spring and leave it attached until well rooted, often until the following year. Softwood cuttings in early summer or semi-ripe cuttings later in summer can also be rooted.

Accepted botanical name

Hydrangea hydrangeoides Schizophragma hydrangeoides is an older name for Hydrangea hydrangeoides.

Native range

Japan, Korea and Kuril Is..

Measured

Average height 700 cm.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.