Styrax, Japanese snowbell: planting, growing, care

Description and botany

In the family Styracaceae, Styrax or aliboufier, also called the “silver-bell tree”, is a bush native to light woodland and riverbanks of Asia, notably Japan and China, but also North America and the Mediterranean Basin. The genus Styrax includes more than a hundred species of bushes or small deciduous or evergreen trees. Only three are commonly found in our gardens: Styrax officinalis, which grows naturally in southern France, S. obassia or “large-leaved Styrax”, and Styrax japonicus (S. japonica) or Japanese styrax, together with numerous cultivars such as ‘Fargesii’, ‘Pendula’ and ‘Pink Chimes’.

This bush, with a single or multiple trunk, displays a bushy, upright or rounded habit, often gracefully spreading, sometimes pendulous (Styrax japonica ‘Pendulus’). Some newer cultivars, such as ‘June Snow’, even show a columnar habit. The branches of Styrax, however, most often tend to grow horizontally, giving it a very elegant layered silhouette. Depending on variety, it forms either small trees or large bushes. The smallest styrax will not exceed about 1 to 2 m in height and, being compact, can be planted anywhere, even in a pot. The largest can reasonably reach up to 6–7 m, rarely more in our regions. Styrax has moderately fast growth and remarkable longevity, since it can live for more than 100 years.

The trunk has a fine smooth brown-grey bark that splits with age.

Styrax develops magnificent foliage from spring to autumn. Its deciduous, alternate leaves are elliptical, ovate or obovate and pointed, with a strongly marked central vein and sometimes finely dentate margins. Large-leaved Styrax (Styrax obassia) is distinguished by large almost round leaves that end abruptly in a point. Leaves, pale green to olive-green and slightly glossy above and downy beneath in spring, turn yellow or orange-red in autumn, extending the shrub’s ornamental interest. Some cultivars display dark purplish foliage, such as Styrax japonica ‘Evening Light’.

Styrax officinalis – botanical illustration by Pierre-Joseph Redouté

Leaves measure from 3 to 20 cm long and stand upright, contrasting with the shrub’s luminous flowering.

In early summer, from May to June, the bush produces a dense, delicate flowering best admired from below! It is clothed in an abundance of small, pendulous, fragrant bell-shaped flowers, grouped in small clusters of three to six at the tips of the year’s shoots. Their corolla, about 1 to 2 cm wide, is formed of five petals most often pure white, sometimes tinged with pink, from which a cluster of stamens with golden-yellow anthers emerges. They recall the flowering of Halesia carolina. Styrax japonica ‘Pink Chimes’ is one of the few varieties to produce pink flowers.

These campanulate bells are melliferous and give off an intense, slightly sweet, vanilla-like fragrance, much prized in perfumery and incense-making.

By mid-summer they give way to small pruinose fruits, ovoid fleshy drupes of a whitish-green colour containing a brown seed.

Perfectly hardy, Styrax can withstand temperatures around -15°C, sometimes lower, and adapts to all regions, provided it is given a sheltered position away from cold winds to protect flower buds from late frosts.

Easy to cultivate, Styrax thrives in partial shade or in sun in a well-drained soil, preferably acidic, rich and humus-bearing. It adapts perfectly to any good garden soil provided it is fresh, only slightly calcareous and well drained.

Its compact yet elegant silhouette and rather slow growth make Styrax a bush suitable for all natural-style gardens, even small spaces, creating attractive focal points.

It can be grown alone as a specimen at the centre or rear of a border or glade, or in groups, in a mixed hedge together with ericaceous bushes. Some modestly growing varieties are well suited to container culture on a terrace or near entrances.

Styrax resin, known as “benzoin“, has been known since Antiquity for its fragrant and medicinal properties, notably antiseptic, antispasmodic and wound-healing. This aromatic substance is also used in the composition of famous incenses and perfumes. Benzoin is also an ingredient in the manufacture of Armenian paper.

Main species and varieties

Of the roughly hundred species in the genus, Styrax officinalis, S. obassia and Styrax japonicus or S. japonica, which occurs in many dwarf, weeping or pink-flowering cultivars, are the species most commonly cultivated.

Our favourites

Styrax japonica

Easy to grow, hardy, it has a very graceful spreading habit. Its reasonable size suits small gardens as well as container culture.

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

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Styrax obassia

Perhaps a little more tender and notable for its large leaves. Ideal along a path, on a terrace or at house entrance to enjoy its delicate fragrance.

• Flowering time June, July
• Height at maturity 6,50 m

See the full description

Planting Styrax

Where to plant Styrax or silver-bell tree?

Hardiness being good, Styrax is able to withstand without problem temperatures from -15 °C to -20 °C and acclimatises throughout France, except perhaps in Mediterranean climate, which is a little too hot and dry in summer.

Avoid exposing it to drying, icy winds that can scorch foliage and damage its flowers, sensitive to late frosts. Plant in a sheltered position in sun, if sun is not too scorching, or in partial shade. It can tolerate full sun except during hottest hours of day. If you live in Mediterranean region, therefore prefer a shaded situation.

Easy to grow, Styrax thrives in any good fresh, well-drained garden soil, preferably non-calcareous, even slightly acidic. In all cases, it is preferable to add a little heather soil at planting.

This bush generally becomes as wide as it is tall: allow a generous, open space.

Plant in a clump, in an informal hedge or as a specimen, it also makes lovely centres for mixed borders. Smaller varieties of Styrax are suitable for container growing on terrace to enjoy its delicate fragrance; this is also a good solution if soil is too calcareous.

When to plant Styrax or aliboufier?

Planting Styrax is preferably done in autumn from September to October, to encourage rooting before winter. Spring planting is also possible once any risk of frost is removed.

How to plant Styrax?

In open ground

For successful planting of your Styrax, also consult our advice sheet: Plant heather soil bushes WHERE AND HOW?

• Dig a hole about twice the size of the root ball
• Add to garden soil some well-rotted compost, one third heather soil and one third coarse sand
• Place the bush, stake, then backfill the hole and firm gently
• Water thoroughly and mulch soil with pine bark to keep it cool in summer
• Continue to water regularly for first three years

Styrax japonica : flowers and fruits

In containers

You can also plant Styrax in a pot: choose the most compact varieties. Plant in a mixture of potting compost, sand and heather soil. Potted Styrax will require more regular watering than in open ground.

Maintenance, pruning and care

Styrax is an easy-to-maintain bush. For first three years after planting, and especially during dry spells, monitor its water needs by watering regularly as soon as soil dries out at surface. Soil should remain cool: it is preferable to mulch around base every spring to retain moisture.

Styrax prefers humus-bearing soil, which is why we recommend adding a little well-rotted compost each spring by forking into soil at base of trunk.

If you live in a cold region, don’t hesitate to cover it with a winter fleece to protect young shoots from frost.

Pruning is not essential, except to rebalance branches or remove crossed or poorly placed branches, or to remove dead wood. It should be carried out in February–March, before growth resumes.

Styrax has no pests or diseases.

Propagation

Sowing Styrax seeds is possible but this delicate technique should be reserved for experienced, patient enthusiasts, especially since a double stratification of seeds is necessary. Prefer propagation by cuttings in August–September, once flowering has finished, on semi-ripe shoots.

• Take cuttings 10 to 20 cm long that are still tender
• Remove leaves from the lower part of stems
• Plant them in pots with potting compost mixed with sand
• Keep moist by watering regularly
• Overwinter them frost-free
• Plant out in ground the following autumn

Pairing Styrax in the garden

Styrax or Silver Bell Tree is a bush offering two seasons of ornamental interest: in early summer when it is covered in white flowering and in autumn when its leaves turn coppery orange and golden yellow.

With its elegant silhouette, it creates pretty focal points in natural, white and romantic gardens. Its delicate white bells will stand out admirably against the evergreen foliage of campanulate Andromedas, Forsythias, Leucothoe and Viburnums.

A planting idea: Styrax japonica, Nepeta faassenii, Phlomis russeliana, Tulip ‘Queen of the Night’, Lupin ‘Gallery Blue’, Rose ‘Fantin Latour’ and Achillea ‘Moonshine’

In a grove, pair it with Halesias, Hamamelis, Magnolias, Mahonias and Fothergillas. In a cool, romantic border, surround its trunk with semi-shade perennials such as epimediums, Phlox divaricata, Melittis, hardy geraniums, Tiarellas, Solomon’s seals, peonies or Dicentra, which will accompany its white flowering.

For a white/silver scheme, plant it near the greyed foliage of Hostas and Brunneras.

This bush, liking acidic soils, is easily associated with ericaceous plants such as Camellias, Azaleas, Rhododendrons, Kalmias, Skimmias, Japanese Andromedas, Sarcococcas or Daphnes. Plant some heathers alongside them.

It will have a most attractive effect alongside shrubs with autumn colour such as the Caramel tree, Acer or Cornus, with which it will be in perfect tonal harmony.