Alangium platanifolium, chinense: planting, cultivation

Description and Botany

Alangium is a deciduous bush belonging to the family Alangiaceae (Cornaceae), related to dogwoods. The genus Alangium comprises 17 species, native to Central and Southern Africa, Asia (Japan, Korea, Philippines), and Oceania. In the wild, it grows in mountains up to 2000 m in altitude in Africa and up to 3000 m in the Himalayas. The Alangiums best suited to our temperate climates are:

1. Alangium platanifolium, Platanus-leaved Alangium
2. Alangium chinense or Chinese Alangium

While in its natural habitat it can reach 18 m, in our climates it will not exceed 2-5 m in height and 2-4 m in width in just 4-5 years. Its habit is broad and rounded. Alangium platanifolium is distinguished from Alangium chinense by a slightly smaller size and a more bushy habit.

With a very rapid growth rate, this large bush displays quite lush foliage, which is deciduous in our climates. It naturally tends to form multiple trunks (a coppice). The branches are tiered and consist of spreading branches that bear remarkably ample deciduous foliage: the leaves of Alangium are long and wide, measuring 3 to 30 cm.

They are alternate, long-petiolate, simple, ovate, and veined in Alangium chinense. This Chinese species stands out for its large, very exotic-looking leaves. Alangium platanifolium is equally interesting for its more elegant foliage reminiscent of that of the plane tree. It is distinguished by deeply lobed leaves (2 to 7 lobes ending in short points). Alangium platanifolium var. macrophyllum is a hybrid with very large leaves.

The branches have a brown bark speckled with white. They are pubescent in the juvenile state and become glabrous once mature. The leaves appear in shades ranging from bright and vivid green to dark green on the upper side, with a lighter underside. They adorn themselves with a lovely golden colour in autumn before falling.

The Alangium offers a summer flowering that is not particularly spectacular but slightly fragrant. In July-August, small pendulous white flowers grouped in clusters 6 to 8 cm long appear in the axils of the leaves. Each cluster contains 12 to 15 fluffy flowers resembling miniature lilies, measuring 2 to 3.5 cm long. They consist of a dentate tubular calyx formed of 6 to 8 lanceolate petals, curled back towards the flower’s pedicel. The stamens with yellow anthers are closely packed along the style.

Alangium platanifolium: bark, foliage, flowers, and fruits

In autumn, this cottony flowering gives way to small ribbed blue-black fruits, ovoid to ellipsoid, inedible, measuring no more than 1.5 cm long.

Perfectly hardy, this remarkable bush can withstand low temperatures of around -18/-20°C and flower the following summer. Its planting is therefore possible in many regions.

The roots of Alangium chinense are among the 50 fundamental plants of traditional Chinese pharmacopoeia.

Main species

Alangium chinense

This large bush with very fast growth is interesting for its large non-lobed leaves with an exotic appearance and its white, fragrant summer flowering.

• Flowering time August, September
• Height at maturity 5 m

See the full description

Alangium platanifolium

It is distinguished from Alangium chinense by a slightly smaller size, a more bushy habit, and particularly elegant deeply lobed foliage.

• Height at maturity 2,50 m

See the full description

Planting Alangium

Where to plant?

With good hardiness, Alangium can withstand temperatures as low as -18/-20°C, ensuring excellent resilience in many regions of our country. It may acclimatise more slowly in a Mediterranean climate, as this forest species is sensitive to overly dry soils in summer.

Plant it in full sun, provided it is not too scorching, or in partial shade. Choose a location sheltered from strong or drying winds that could scorch its foliage and damage its flowers.

Not demanding, it appreciates any good garden soil that is fresh, with a neutral or slightly acidic pH, even calcareous, humus-bearing, and well-drained, avoiding stagnant moisture around the roots. It will even thrive in ordinary soil. The soil can be slightly moist as long as water does not stagnate.

In a garden, this rare bush in cultivation always introduces an original focal point. It can be grown either as a specimen in a large garden, at the back of a border, or in the foreground of an evergreen hedge. This bush, which prefers slightly acidic soil, can easily be paired in the background of a border with ericaceous plants.

When to plant?

Planting Alangium can be done in spring from February to April or preferably in autumn from September to October, to encourage root establishment before winter.

How to plant?

• Prepare a large planting hole of 80 cm x 60 cm with a mix of half native soil, heather soil, and compost
• Plant it at collar level without burying the root ball too deeply
• Keep the bush upright and stake it
• Firm the soil lightly
• Mulch around the base
• Water generously

The Alangium chinense integrates easily into all gardens

Maintenance and pruning

Alangium is one of the easiest bushes to maintain. It can show slight suckering: regularly remove the shoots if you wish to keep a beautiful shape and a single trunk for your bush.

In dry weather, monitor your bush’s water needs, especially in the first few years. It is advisable to mulch the base every spring with a good layer of bark mulch or pine needles to prevent soil evaporation and maintain a proper level of moisture in the soil.

Pruning is not essential, except to rebalance the branches or maintain a nice shape. It is easy to prune. Each autumn, shorten the previous year’s shoots by 2/3 or ¾ of their length to keep a more compact bushy habit. In spring, in March, remove dead wood and crossed branches to allow light to penetrate the centre of the branches. Make the cut with a pruning shear with sharp, curved blades that have been disinfected with alcohol, or even with a lopper.

In our gardens, it is free from diseases and pests.

Multiplication

To propagate Alangium, propagation by cuttings yields good results, and it is also possible to collect suckers.

By Cuttings

Take herbaceous cuttings in spring or semi-woody cuttings in August-September.

1. Take cuttings of 10 to 20 cm without flowers, cutting just below an eye, from the current year’s shoots with a semi-hardened base
2. Remove the lower leaves from the stem
3. Plant in a tray, spacing them 10 cm apart, or in pots using a light, well-draining substrate kept moist
4. Cover to create a humid environment
5. Transfer to pots as soon as the cuttings have formed roots
6. Overwinter them in a frost-free environment
7. Transplant them into the ground the following spring

Associate

Alangium is one of those trees that offers gardeners two seasons of interest: in summer when it is covered in white flowers and lush green foliage, and in autumn when its leaves turn bright yellow.

It integrates easily into both modest-sized gardens and parks, punctuating a lawn, dominating a bed of lower bushes, or blending into a hedge. It will happily find its place in natural gardens or in compositions inspired by exotic themes.

To fully enjoy its beauty, plant it against a backdrop of permanent and utilitarian greenery composed of conifers and evergreen bushes.

Flowering dogwoods (Cornus alba, Cornus florida) as well as summer magnolias and white ceanothus are good companions to accompany its delicate flowering. At the end of the season, Caramel tree or Acer palmatum will enhance its autumn foliage.

An idea for association: Andromeda and Hydrangea macrophylla under the cover of a beautiful Alangium chinensis

This bush, which prefers acidic soils, can easily be associated in the background of a bed, with ericaceous plants such as Andromedas, Azaleas, Hydrangea macrophylla and Hydrangea serrata, or even Daphnes.

It can also be installed within a bed of tropical-looking but fairly hardy plants, such as banana plants, a Tetrapanax papyfera Rex, or a giant canna, for a guaranteed exuberant effect!