<em>Schizophragma hydrangeoides</em>: planting, cultivation, care

Description and botany

Schizophragma originates from wooded, humid regions of Asia (Japan, Himalaya, Taiwan). Belonging to family Hydrangeaceae, like Deutzias or mock-oranges, its closest relative is Hydrangea petiolaris, another climbing hydrangea to which it bears resemblance. It is distinguished, however, by a more spectacular flowering in large inflorescences with highly decorative bracts. Introduced to Europe in late 19th century and honoured by the Royal Horticultural Society for its beauty, it remains a relatively little-known and rarely used plant.

Schizophragma, also called ‘Japanese climbing hydrangea’ or ‘false climbing hydrangea’, is a woody climbing plant. It is a rooting liana with twisting branches that attaches itself to supports thanks to aerial roots but, unlike ivy, its climbing roots do not damage structures. Slow-growing, this climbing hydrangea needs 2 to 3 years to establish properly and requires training at first.

There are 4 or 5 species cultivated in gardens. Some do not exceed 4 metres in height, such as Schizophragma ‘Moonlight’ or Schizophragma corylifolium. Others are more vigorous and demand suitable supports. This is the case for Schizophragma fauriei, giant of the genus, which can reach nearly 15 m. Spread rarely exceeds 3 to 4 metres.

The false climbing hydrangea produces main stems that grow vertically. Along these framework branches are produced lateral branches bearing the inflorescences. Between May and August, and for nearly three weeks, many small flowers appear at branch tips, in flattened cymes. Fertile and melliferous, they are much appreciated by pollinating insects. This climber attracts attention above all by its large bracts surrounding the flowers. Carried on long petioles, elongated and pointed in shape, they seem to float around the plant. In the wind, these ‘tears’ give the impression that a cloud of butterflies has taken possession of the place. The inflorescences then dry and remain decorative until winter.

Mostly ivory-white, the bracts are delicately tinged with pink in a single variety, Schizophragma ‘Rose Sensation’, sometimes marketed under name ‘Roseum’.

Inflorescences of false climbing hydrangeas: Schizophragma hydrangeoides, S. hydrangeoides ‘Rose Sensation’ and S. integrifolia

Schizophragma integrifolia is perhaps the most spectacular with its white inflorescences, larger (up to 30 cm) and more graceful.

Slow to establish, Schizophragmas may not flower during first 2 or 3 years but once established, they become more attractive each year.

With a dense habit, Schizophragma bears opposite, heart-shaped leaves. Sometimes pubescent with slightly dentate margins.

Foliage, deciduous to semi-evergreen, is of a more or less deep green, except in Schizophragma ‘Moonlight’ which reflects silvery tones that highlight darker veins. It also takes on beautiful autumn colours and turns a deep red.

Schizophragma ‘Angel Wings’ is also notable for grey-tinged foliage.

All Schizophragmas prefer fairly fertile, humus-bearing, fresh but well-drained soils. They tolerate neutral soils but show a preference for slightly acidic soils. They can grow in heavier, clay soils provided water does not stagnate there during wet season.

An understorey liana, flowering of the false climbing hydrangea is at its best in partial shade or light shade. It tolerates denser shade but is less showy there. Sunny exposure is possible provided it is not scorching (avoid south-facing walls) and soil remains cool.

Schizophragma is very resistant to diseases but young shoots can attract slugs and snails. Natural control methods exist, and this risk mainly applies to young plants. Aphids may also settle on the plant but do not represent a major threat. In case of heavy infestation, find out how to limit their presence.

Different varieties of Schizophragmas

Most popular varieties

Varieties to discover

Schizophragma hydrangeoides

This is the type species, with dark green foliage that highlights its 20 cm inflorescences of luminous white. Moderate growth.

• Flowering time July to September
• Height at maturity 10 m

See the product sheet

Schizophragma hydrangeoides Rose Sensation

It is the only one to display pale pink tones, forming a soft, airy tapestry that adds a lovely romantic touch.

• Flowering time July, August
• Height at maturity 6 m

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Schizophragma hydrangeoïdes Moonlight

A variety with superb green foliage with silvery grey reflections highlighted by well-defined dark veins. Faster growth than the type.

• Flowering time July, August
• Height at maturity 4 m

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Schizophragma hydrangeoides Windmills

A variety with moderate development and fairly rapid growth. Well suited to container cultivation on a terrace or balcony.

• Flowering time July to September
• Height at maturity 5 m

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Schizophragma integrifolium

A species with vigorous development but somewhat less hardy, to be reserved for mild regions. Spectacular pure white flowering!

• Flowering time July to September
• Height at maturity 8 m

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Schizophragma corylifolium

Earliest of all, it flowers in late spring or very early summer. Its light green foliage and cream-coloured flowers give it a natural, romantic charm.

• Flowering time June to August
• Height at maturity 4 m

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Schizophragma fauriei

A very vigorous liana without being invasive, with dense, leafy branches. Very hardy, ideal for screening a large unsightly wall.

• Flowering time August, September
• Height at maturity 15 m

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Schizophragma fauriei Angel Wings

Selected for its spectacular flowering, this cultivar displays beautiful leaves tinted grey, with tin-coloured veins.

• Flowering time August, September
• Height at maturity 15 m

See the product sheet

Where, when and how to plant Schizophragmas?

Where to plant?

Schizophragma prefer bright to semi-shaded positions where light favours flowering. In cooler regions north of the Loire, planting in sun is possible. Further south, a north-facing aspect is an option.

Plant false climbing hydrangea in rich, deep, humus-bearing soil. Prefers acidic soils but accepts neutral soils. If needed, add heather soil or turf, and well-rotted compost, to which add a handful of crushed horn. In any case, avoid calcareous soils.

Although it can tolerate occasional drought once established, prefer soil that remains fresh but not waterlogged, especially in winter.

Japanese climbing hydrangea is a liana and needs a support to cling to. Install on trunk of a deciduous tree or beneath one where shade is not too dense, train it up a wall, let it drape over a pergola of suitable dimensions or cloak a garden shed with its delicate flowering.

On a terrace or large balcony, plant Schizophragma in a pot of good size (minimum 50 cm in all directions) and use it to hide a stretch of wall or climb a trellis.

In any case, Schizophragma is slow to establish. Allow 2–3 years before it really takes off (and flowers). To help it, and before it can cling by itself, guide and stake its branches.

Once well established, growth accelerates and flowering becomes more generous each year.

When to plant?

Plant Schizophragma ideally in autumn, when soil is still warm and seasonal rains ensure necessary freshness. Planting in spring is also possible; in that case, water regularly if weather is dry.

How to plant?

Planting in open ground :

1. Begin by soaking the rootball in a generous volume of water so substrate is thoroughly moistened.

2. Ideally, dig a hole 2–3 times the width of the rootball and about 50 cm deep. Adapt planting distance to chosen support:

– Plant at base of a post if training Schizophragma up a pergola, for example.

– If support is a tree, find a pocket of soil between two large roots, about 50 cm from the trunk. Dig carefully to avoid damaging major roots and cut small ones cleanly with a pruning shear. When positioning, orient plant obliquely towards trunk.

– Against a facade, an overhang may deprive plant of some or all rainwater. In that case, move planting hole away to offset this (or check soil freshness regularly!).

3. Place a 5 cm layer of gravel in bottom of hole to ensure good drainage.

4. Optionally place a stake in planting hole and angle it towards the support to help the liana cling. After 2–3 years it will manage on its own.

5. Mix excavated soil with quality potting compost or heather soil, and a shovelful of well-rotted compost. Add a handful of crushed horn to feed plant in the long term.

6. Remove rootball from container and place it in the hole, filling with the mixture.

7. Firm lightly and form a basin to help water reach roots.

8. Water thoroughly so soil adheres well to roots.

9. Secure main branches to the stake with soft ties and without strangling shoots.

10. Mulch the base using dead leaves, dried grass clippings, ramial chipped wood (BRF) or commercial mulches (flax shives, buckwheat or coconut husks, pine bark…). A thickness of several centimetres guarantees good freshness at base of plant.

Planting in a pot :

Soil volume being necessarily smaller in a pot than in open ground, plant growth is generally reduced. Container size therefore matters. The larger it is, the more nutrients and moisture plant has. A pot of at least 50 cm in all directions is minimum for a climber such as Schizophragma. Ensure pot has drainage holes so water does not stagnate. Fresh soil does not mean waterlogged!

1. Soak the rootball so it becomes evenly saturated.

2. Mix 1/3 heather soil with 2/3 rich potting compost. Turf, once dry, is very difficult to rehydrate and Japanese climbing hydrangea needs a fresh soil. Add a handful of crushed horn to feed plant in the long term.

3. Place a 5 cm layer of gravel in pot base. Lay a geotextile over the gravel to prevent soil mixing with this drainage layer.

4. After possibly placing a stake in the pot (unnecessary if plant will climb a trellis, for example), place rootball and fill with the mix.

5. Firm lightly. Leave 2–3 cm between substrate surface and top of pot. This allows easy mulching and watering.

6. Orient Schizophragma towards its support and secure main branches (without strangling) with soft ties.

7. Water gradually until water runs out of drainage holes.

8. Mulch to maintain freshness. Use organic mulches (bark, flax shives…) or mineral (gravel, pebbles, slate chips…) according to chosen style.

Using a saucer ensures a reserve of water for plant in hot season but it must be removed during winter so roots remain dry. However, the larger the pot the heavier and more difficult to handle. You may also damage plant (fixed to its support) when moving. An alternative is to fill saucer with clay balls before placing pot. Even when saucer is full of water, roots remain dry, but evaporation creates a more humid, cooler atmosphere beneficial to plant.

Caring for Schizophragmas

During the main growing season, if rainfall is scarce, water regularly, especially during the first few years. Once established, Schizophragma can tolerate short periods of drought. Prefer a thorough watering once a week rather than small daily amounts, except in pots where the substrate dries more quickly.

In winter, natural rainfall is usually sufficient. Intervene only if necessary and always outside periods of severe frost, especially if plant is in a pot.

Each year in spring, add compost and replace a generous layer of mulch. Incorporate a handful of blood meal at the end of spring. This quick-acting fertiliser boosts flowering.

In pots, remove mulch at the start of spring, also add compost or a rich potting mix enriched with horn meal and replace the mulch. From May to August, feed monthly with a suitable fertiliser (follow dosage instructions on packaging) but never on dry potting mix.

Pruning Schizophragma is not obligatory. It is not necessary in the early years as its growth is slow.

If needed, prune in late winter or early spring. Remove any dead wood and cut back misplaced or overly long stems to suit.

Schizophragmas are hardy plants. Only slugs and aphids may attack young foliage. Discover how to fight slugs naturally and how to identify and control aphids.

Propagating Schizophragmas

False climbing hydrangea is slow-growing, especially during first 2 to 3 years. If you want to multiply it, wait until it is well established.

Multiplication can be done by propagation by cuttings in summer or by layering.

Propagation by cuttings of Schizophragma

Propagation by cuttings is carried out in summer (between July and September)

• In a pot, make an equal-parts mix of light potting compost combined with sand or finely shredded bark. Mix must be free-draining but able to retain moisture.
• Choose a piece of semi-herbaceous stem (base slightly firmer and tip more tender) 6 to 10 centimetres long.
• Cut just below a node (swelling where a stem is inserted) with a disinfected pruning shear.
• Prepare the cutting: remove any side shoots and leaves, leaving only two at the tip of the cutting. Cut remaining leaves in half to limit evaporation.
• Using a knife or the blade of pruning shear, slightly wound the base of the cutting. The operation consists in removing only a very superficial layer of tissue, about 1 centimetre, without reaching inner layers of the stem. If desired, you can dip the base of your cutting in plant hormone, sold in garden centres, often as a powder. Tap the cutting to remove excess powder.
• Make a pilot hole in substrate using a pencil for example and insert your cutting until leaves are level with substrate then water gently so as not to disturb the cutting.
• Cover potting compost with a thin layer of gravel which helps keep freshness by limiting evaporation.
• Cut off top of a plastic water bottle and place it over the pot. Kept like this under a mini-cloche, the cutting roots faster and more easily. Simply remember to remove it for a few minutes each day to air the whole.
• Place cuttings outdoors in a bright spot but out of direct sun and check regularly that potting compost remains moist but not waterlogged.
• Appearance of new leaves indicates successful take. Continue monitoring (occasional watering, airing) and plant cutting in its final position in autumn of following year.

Layering of Schizophragma

Layering is a process that sometimes occurs spontaneously in nature and which gardener can also induce. Part of the plant in contact with soil will produce roots that then give rise to an independent plant.

Layering can be done all year, but prefer March or autumn.

• Prepare soil a few centimetres from base of your Schizophragma. Turn soil over about thirty centimetres in all directions, remove stones and weeds. Add light, free-draining potting compost and mix well with original soil.
• Choose a stem under 2 years old, growing near ground, flexible enough to be handled without breaking. It must be long enough to be laid on the ground for at least 60 centimetres.
• Keep tip of stem intact for 15 to 20 centimetres. Remove leaves or any branches from the middle section then, using a disinfected knife or blade of pruning shear, make a slight incision in the bark for a few centimetres. Make the incision on the side of the stem that will face the soil.
• Make a small trench in prepared soil, lay the stem into it so that the incised section is in contact with the soil then cover with a few centimetres of soil.
• Secure the layered stem using metal staples or a suitably heavy stone.
• Gently raise the tip of the stem by tying it upright to a stake planted in the soil.
• Water and check regularly that substrate does not dry out.
• After one year, the layer will have produced roots at the incision site. It is then time to wean it off. Cut the branch a few centimetres before the new roots, lift your new plant gently and pot it up to strengthen a little more or plant straight into ground.

Combining Schizophragmas in the garden

Climbing plant for light shade, Schizophragmas pair well with many trees with sparse foliage, such as an old fruit tree that flowers in spring and whose trunk is then covered in flowers in summer.

In a bright spot, pair the Schizophragmas with other flowering climbers such as an Akebia or a Clematis or with lianas whose foliage lights up in autumn, such as Ampelopsis or Parthenocissus.

An example of an understorey association: a Schizophragma hydrangeoides climbs a tree with at its base a Hydrangea macrophylla and a carpet of dead-nettles as groundcover

Play contrasts of shapes and textures with foliage of ivies, some of which offer very attractive variegation.

In mild climates, Berberidopsis flowers at the same time in clusters of red bell-shaped flowers.

Dress their base with hydrangeas whose inflorescences echo those of the climber. Hydrangea aspera ‘Hot Chocolate’ provides a striking contrast with its very dark foliage that turns golden in autumn.

Did you know?

The name Schizophragma comes from ancient Greek ‘schizo’ (“to split”) and ‘phragma’ (“screen, barrier”). The origin of its name simply refers to the shape of its fruiting bodies. So no need to panic! This beautiful liana will not split the wall it climbs. Unlike other climbing plants, such as ivy, Schizophragma never damages its support.