<em>Styrax</em>, aliboufier: planting, growing and caring for

Description and Botany

Of the family Styracaceae, Styrax or storax, also called “silver-bell tree”, is a bush native to light woodland and riverbanks in Asia, particularly Japan and China, but also North America and Mediterranean basin. Genus Styrax includes more than a hundred species of bushes or small deciduous or evergreen trees. Only three occur 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 its numerous cultivars such as ‘Fargesii’, ‘Pendula’ or ‘Pink Chimes’.

This bush, with a single or multiple trunk, presents a bushy, upright or rounded habit, often gracefully spreading, sometimes pendulous (Styrax japonica ‘Pendulus’). Some newer cultivars such as ‘June Snow’ even exhibit a columnar habit. Branches of Styrax, however, most often tend to grow horizontally, giving it a very elegant tiered silhouette. Depending on variety, it forms small trees or large bushes. The smallest styrax will not exceed about 1–2 m in height; unobtrusive, they can be planted anywhere, even in a pot. The largest may reasonably reach up to 6–7 m, rarely more in our regions. Styrax’s moderately fast growth is matched by its longevity, as it can live for more than 100 years.

Trunk bears a beautiful smooth brownish-grey bark that fissures 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 midrib and sometimes finely dentate. Large-leaved Styrax (Styrax obassia) is distinguished by large, almost round leaves ending abruptly in a point. Leaves, soft green to olive-green, slightly glossy above and pubescent beneath in spring, turn yellow or orange-red in autumn, extending ornamental interest of the bush. Some cultivars display almost black-purple foliage, such as Styrax japonica ‘Evening Light’.

Styrax officinale – botanical illustration by Pierre-Joseph Redouté

Leaves measure 3–20 cm long and stand erect toward sky, contrasting with bush’s luminous flowering.

In early summer, from May to June, the bush displays a dense, delicate flowering that is best admired from below! It is adorned with an abundance of small, pendulous, fragrant campanulate flowers, gathered in small clusters of three or six at tips of current-year shoots. Their corolla, about 1–2 cm wide, is formed of 5 petals, most often pure white, sometimes tinged with pink, from which emerges a bouquet of stamens with golden-yellow anthers. They recall flowering of Halesia carolina. Styrax japonica ‘Pink Chimes’ is one of the rare varieties to offer pink flowers.

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

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

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

Easy to grow, Styrax thrives in partial shade or in sun in a well-drained, rather acidic, rich, humus-bearing soil. It adapts perfectly to any good garden soil provided it is fresh, not too calcareous and well drained.

Its compact yet elegant habit and fairly slow growth make Styrax a bush that finds its place in all natural gardens, even in small spaces, forming attractive focal points.

It can be grown either alone as a solitary specimen in centre or at back of a border or clearing, or in groups, in a mixed hedge combined with heather-soil bushes. Some modestly sized varieties are well suited to container culture on a terrace or near entrances.

Styrax resin, called “benzoin”, has been known since antiquity for its aromatic and medicinal properties, notably antiseptic, antispasmodic and wound-healing. This aromatic substance is also used in composition of incense and famous perfumes. Benzoin is also used in manufacture of Armenian paper.

Main species and varieties

Among roughly one hundred species in the genus, Styrax officinalis, S. obassia and Styrax japonicus or S. japonica, which declinate into numerous dwarf, weeping or pink-flowered cultivars, are the species most commonly cultivated.

Our favourites

Styrax japonica

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

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

See the product sheet

Styrax obassia

It may be somewhat less hardy and is notable for its large leaves. Ideal along a path, a terrace or by the house entrance to enjoy its delicate fragrance.

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

See the product sheet

Planting Styrax

Where to plant Styrax or silver-bell tree?

With good hardiness, Styrax is capable of withstanding without problem temperatures of -15 °C to -20 °C and acclimatises across France, except perhaps in Mediterranean climate, a little too hot and dry in summer.

However, avoid exposing it to drying and freezing winds that can scorch its 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, prefer a shaded situation.

Easy to grow, Styrax thrives in any good fresh, well-drained garden soil, preferably non-calcareous, even with an acidic tendency. In all cases, better to add some heather soil at planting.

This bush generally becomes as wide as tall: allow a spacious, well-cleared location.

Plant in small grove, as informal hedge or as specimen, it also makes pretty centres for beds. Smaller varieties of Styrax are suitable for growing in pots on terrace to enjoy its delicate fragrance; also a good solution if soil is too calcareous.

When to plant Styrax or Aliboufier?

Planting of Styrax is preferably done in autumn from September to October, to favour rooting before winter. Spring planting is also possible when all risk of frost is past.

How to plant Styrax?

In ground

To succeed with planting your Styrax, also see our advice sheet: Plant heather soil bushes WHERE AND HOW?

• Dig a hole about twice size of root ball
• Add to garden soil some well-rotted compost, 1/3 heather soil and 1/3 coarse sand
• Place bush, stake it then backfill hole and firm gently
• Water well and mulch soil with pine bark to maintain freshness in summer
• Continue to water regularly during first three years

Styrax japonica : flowers and fruits

In pot

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

Maintenance, pruning and care

Styrax is an easy-to-care-for bush. During the first three years after planting, and especially in dry periods, monitor water needs by watering regularly as soon as the soil dries at the surface. The soil should remain cool: it is preferable to mulch the base every year in spring to maintain moisture.

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

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

Pruning is not essential, except to rebalance the branches or remove crossing or poorly placed branches, or to eliminate dead wood. It is carried out in February-March, before growth resumes.

Styrax has no pests or diseases.

Multiplication

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

• Take cuttings 10–20 cm long while still soft
• Remove leaves from base of stems
• Plant them in pots filled with potting compost mixed with sand
• Keep moist by watering regularly
• Overwinter them frost-free
• Plant out in ground the following autumn

Pairing Styrax with other plants in the garden

Styrax or silver-bell tree is a bush that offers two seasons of ornamental interest: at start of summer when it is covered in its 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 gardens, white gardens and romantic gardens. Its delicate white bells will stand out beautifully against evergreen foliage of campanulate Andromedas, Forsythias, Leucothoe, Viburnums.

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

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

For a white/silver harmony, place it near greyed foliage of Hostas and brunneras.

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

It will look splendid alongside shrubs with autumn colours such as Caramel tree, Acer or Cornus, with which it will be in perfect tonal harmony.