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

Description and botany

Schizophragma originates in wooded, humid regions of Asia (Japan, Himalaya, Taiwan). Belonging to family Hydrangeaceae, like Deutzia and mock orange, its closest relative is Hydrangea petiolaris, another climbing hydrangea to which it bears resemblance. It differs, however, by a more spectacular flowering in large inflorescences with very decorative bracts. Introduced to Europe at the end of 19th century and awarded by Royal Horticultural Society for its beauty, it remains fairly little known and underused.

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

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

False climbing hydrangea produces main branches that grow vertically. Along these framework branches are produced lateral branches that bear the inflorescences. Between May and August, for about three weeks, many tiny flowers appear at branch tips, in flattened cymes. Fertile and melliferous, they are much appreciated by pollinators. This climber attracts attention above all by its large bracts that surround the flowers. Carried on long petioles, elongated and pointed, they seem to float around the plant. In wind, these ‘teardrops’ give the impression that a cloud of butterflies has taken possession of the space. The inflorescences then dry and remain decorative through winter.

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

Inflorescences of False Climbing Hydrangeas: Schizophragma hydrangeoides, S. hydrangeoides ‘Rose Sensation’ and S. integrifolia

Schizophragma integrifolia may be 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 charm more each year.

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

Foliage deciduous to semi-evergreen is variously deep green, except in Schizophragma ‘Moonlight’ which shows silvery reflections that highlight darker veins. It also takes beautiful autumn colours and turns a deep red.

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

All Schizophragmas prefer fairly fertile soils, rich in humus, fresh but free-draining. They accept neutral soils but show a preference for soils tending acidic. They can grow in heavier, clay soils provided water does not stagnate there during poor seasons.

As an understorey liana, flowering of false climbing hydrangea is at its best in partial shade or light shade. It tolerates denser shade but is then more discreet. Sunny exposure is possible provided it is not scorching (avoid south-facing walls) and soil retains good freshness.

Schizophragma is very disease-resistant but young shoots may attract slugs and snails. Natural control methods exist, and this risk mainly concerns young plants. Aphids may also take up residence in the plant but do not pose significant danger. In case of heavy infestation, discover how to limit their presence.

Different varieties of Schizophragmas

Most popular varieties

Varieties to discover

Schizophragma hydrangeoides

Type species with dark green leaves showcasing 20 cm inflorescences of bright white. Moderate growth.

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

See the product sheet

Schizophragma hydrangeoides Rose Sensation

Only one to display pale pink hues, forming a tapestry of softness and lightness that adds a romantic touch.

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

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Schizophragma hydrangeoïdes Moonlight

Variety with superb green leaves with silvery-grey highlights, emphasised by well-defined dark veins. Growth faster than type.

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

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Schizophragma hydrangeoides Windmills

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

Species with vigorous development but slightly less hardy, best 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, flowers in late spring or early summer. Its light-green foliage and cream flowers give it natural, romantic charm.

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

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Schizophragma fauriei

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

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

See the product sheet

Schizophragma fauriei Angel Wings

Selected for spectacular flowering, this cultivar displays beautiful grey-tinged leaves 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?

Schizophragmas like bright to semi-shaded positions where light favours their flowering. In regions north of the Loire with cooler climates, planting in full sun is possible. Further south, a north-facing exposure is an option.

Plant your ‘False climbing hydrangea’ in rich, deep, humus-bearing soil. It prefers acidic soils but accepts neutral soil. If necessary, add heather soil or turf, and compost, to which add some crushed horn. In any case, avoid calcareous soils.

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

Japanese hydrangea vine is a liana and needs a support to cling to. Plant it on the trunk of a deciduous tree or beneath one where shade is not too dense, train it up a wall, let it festoon a pergola of suitable size, or wrap a garden shed in its delicate blooms.

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

In all cases, Schizophragma is slow to establish. Allow 2 to 3 years before it really gets going (and before it flowers). To help it, and before it can cling unaided, guide and stake its branches.

Once well established its growth speeds up and flowering becomes more generous each year.

When to plant?

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

How to plant?

Planting in ground :

1. Start by soaking the root ball in plenty of water so the whole substrate becomes uniformly moist.

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

– Plant at the 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 prune small roots cleanly with a pruning shear. When positioning, angle the plant obliquely towards the trunk.

– Against a façade, the presence of an overhang may deprive the plant of all or part of the rainwater. In that case, move the planting hole to compensate (or check soil moisture regularly!).

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

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

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

6. Remove the plant from its pot and place it in the hole, backfilling with the mixture.

7. Firm soil gently and form a saucer to help water reach the roots.

8. Water thoroughly so soil adheres well to the roots.

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

10. Mulch the base using dead leaves, dried grass clippings, BRF (ramial chipped wood) or commercial mulches (flax shavings, buckwheat hulls or coconut husks, pine bark…). A layer several centimetres thick ensures the soil at the plant base stays cool.

Planting in a pot :

Soil volume in a pot is naturally smaller than in open ground, so growth is generally more limited. Container size matters: the bigger it is the more nutrients and moisture the plant has available. A pot 50 cm in all directions is the minimum for a climber such as Schizophragma. Make sure the pot has drainage holes so water does not stagnate. Fresh soil does not mean waterlogged!

1. Soak the root ball so it becomes evenly saturated with water.

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

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

4. After optionally placing a stake in the pot (unnecessary if the plant will climb a trellis, for example), place the root ball and backfill with the mix.

5. Firm lightly . Leave 2 to 3 cm between substrate surface and rim of pot. This makes mulching and watering easier.

6. Orient Schizophragma towards its support and fix main branches (without strangling them) using soft ties.

7. Water little by little until water runs out of the bottom of the pot.

8. Mulch to maintain coolness. Use organic mulches (bark, flax shavings…) or mineral ones (gravel, pebbles, slate chips…) depending on chosen style.

Using a saucer provides a water reserve for the plant in hot weather but it should be removed in winter so roots stay dry. However, larger pots are heavy and difficult to handle and you may damage the plant (fixed to its support) when moving it. An alternative is to fill the saucer with clay balls before placing the pot. Even when the saucer is full of water, roots remain dry, but evaporation creates a more humid, cooler atmosphere beneficial to the plant.

Caring for Schizophragmas

During the growing season, if rainfall is scarce, water regularly, especially during the first years. Once established, Schizophragma can withstand short periods of drought. Prefer a thorough watering once a week rather than small daily amounts of water, except in a pot 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.

Every spring, add compost and replace a good layer of mulch. Incorporate a handful of dried blood in late spring. This quick-acting fertiliser boosts flowering.

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

Pruning of Schizophragma is not obligatory. It is not necessary anyway during the first years because growth is slow.

If needed, intervene at the end of winter or the start of spring. Remove any dead wood and cut back stems that are poorly placed or too long to suit your taste.

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

Propagating Schizophragmas

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

Multiplication may be carried out by propagation by cuttings in summer or by layering.

Propagation by cuttings of Schizophragma

Propagation by cuttings is done 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 should be free-draining but capable of retaining moisture.
• Choose a piece of semi-herbaceous stem (base a little firmer and tip more tender) 6 to 10 cm long.
• Cut just below a node (swelling where a stem inserts) with a disinfected pruning shear.
• Prepare the cutting: remove any side stems and leaves, leaving only two at the top of the cutting. Cut remaining leaves in half to limit evaporation.
• Using a knife or the blade of your pruning shear, slightly wound the base of the cutting. Remove only a very superficial layer of tissue, about 1 centimetre, without reaching internal layers of the stem. Optionally, 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 your substrate using a pencil for example, insert the cutting until the leaves are level with the substrate then water gently so as not to disturb the cutting.
• Cover surface compost with a thin layer of gravel which helps to maintain coolness by reducing evaporation.
• Cut off top of a plastic water bottle and place it over the pot. Kept as a mini greenhouse, the cutting will root faster and more easily. Remember to remove it for a few minutes each day to air the contents.
• Place cuttings outdoors in a bright spot but out of direct sun and check regularly that compost remains moist but not waterlogged.
• Appearance of new leaves indicates successful take. Continue monitoring (watering if necessary, airing) and plant the cutting in position in autumn of following year.

Layering of Schizophragma

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

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

• Prepare soil a few centimetres from base of your Schizophragma. Turn soil about 30 centimetres in all directions, remove stones and weeds. Add light, free-draining potting compost and mix well into original soil.
• Choose a stem less than 2 years old, growing near ground, flexible enough to handle without breaking. It should be long enough to be laid on soil for at least 60 cm.
• Keep tip of stem intact for 15 to 20 cm. Remove leaves or any branches from middle then, using a disinfected knife or blade of a pruning shear, make a slight incision in the bark over a few centimetres. Make incision on side of stem that will face the soil.
• Make a small trench in prepared soil, lay the stem so incised section is in contact with soil then cover with a few centimetres of soil.
• Secure the layered stem using metal staples or a sufficiently heavy stone.
• Gently lift the tip of the stem and tie it vertically to a stake planted in the soil.
• Water and check regularly that substrate does not dry out.
• After one year, layered section will have produced roots at incision site. It is then time to sever. Cut the branch a few centimetres before new roots, gently lift your new plant and pot it up to strengthen it further or plant directly in ground.

Pairing Schizophragmas in the garden

Climbing plant for light shade, Schizophragmas pair with many trees with sparse foliage, such as an old fruit tree with spring flowering whose trunk becomes covered with flowers in summer.

In a bright position, pair the Schizophragmas with other flowering climbers such as Akebia or a Clematis or with lianas whose foliage turns fiery in autumn, such as Ampelopsis or Parthenocissus.

An example of an understorey association: a Schizophragma hydrangeoides climbs a tree with at its foot a Hydrangea macrophylla and a tapetum of lamiums as groundcover

Play contrasts of shape and texture with foliage of the ivies, some of which offer very attractive variegation.

In mild climate, 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 handsome contrast with its very dark foliage which turns golden in autumn.

Did you know?

The name Schizophragma derives from ancient Greek ‘schizo’ (‘to split’) and ‘phragma’ (‘screen, barrier’). The origin of its name simply refers to the shape of its fruiting structures. 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.