Common Name: Tree Of Heaven

General Information

Ailanthus altissima is a deciduous tree with a densely-branched, rounded crown; it usually grows 15 - 20 metres tall, but can reach 30 metres. The bole can be 60 - 90cm in diameter[]. The tree sends up suckers freely and can soon form dense thickets[, , ].
The tree has a wide range of medicinal uses and is often used in China and other Asian countries, though little used in the West. Because of its tolerance of poor growing conditions and its extensive root system, it is often used in soil stabilization and reclamation projects. It is occasionally cultivated for its wood[]. A very ornamental tree, with its large leaves it has a somewhat tropical appearance and is fast growing when young[, , ], though it is rather short-lived[]. The tree thrives even when growing in very polluted cities[, ] and so has been used as a street tree and as a shade-tree in parks[]
Widely cultivated as an ornamental, the plant has escaped and become naturalized in many countries outside its native range. It is able to grow in almost any situation, succeeding in heavily polluted cities and able to grow through cracks in pavements, for example. It can spread rapidly on undisturbed grazing land, roadsides and waste places, on both clay and sandy soils. In many areas it is considered to be a noxious weed since it forms dense thickets that can out-compete native species and damage natural environments[, , , ].

Known Hazards

The plant is possibly poisonous[, ]. Male flowers have potentially allergenic pollen[].
The leaves are toxic to domestic animals[]. Gardeners who fell the tree may suffer rashes[]. The odour of the foliage is intensely disagreeable and can cause headache and nausea, rhinitis and conjunctivitis[].The pollen can cause hay fever[].

Botanical References

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Range

E. Asia - China - found in nearly all areas. Naturalized in many other countries.

Habitat

Found in a wide range of habitats at elevations from 100 - 2,500 metres[]. Uplands[].

Properties

Weed Potential	Yes
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	25.00 m
Growth Rate	Fast
Pollinators	Bees
Self-fertile	No
Cultivation Status	Ornamental, Wild

Cultivation Details

Ailanthus altissima is a very adaptable tree that can be grown in temperate to subtropical climates. The tree is estimated to tolerate a mean annual precipitation in the range of 300 - 2,500mm, and to tolerating a dry season of up to 8 months. It succeeds in areas where the mean annual temperature is in the range of 10 - 20°c[]. Dormant plants are hardy to at least -15°c[].
Prefers a position in full sun or partial shade[]. Grows best in a light moist soil and in a sheltered position, but can succeed in soils from sandy to light clay, from well-drained to swampy, and on both poor or rich, though it is said to do poorly on chalky soils or compact clay[]. A very tough and easily grown tree, it succeeds under most conditions, being said to be tolerant of both alkaline and acid soils; poor, dry or wet soils; heavily polluted soils; drought; and atmospheric pollution, including sulphur dioxide and hydroden chloride[, ].
The roots are rather aggressive and can cause damage to drainage systems[].
The plant produces a toxin in its bark and leaves - this gradually accumulates in the soil as the leaves etc decay. The toxin inhibits the growth of other plants[].
The plant is resistant to most diseases[].
Male flowers are malodorous and have potentially allergenic pollen, so only female trees are recommmended for street planting[, ]. The crushed leaves are also malodorous[]. The large leaves have glandular teeth near their base and these release a pungent aroma when pressed[]. The disagreeable odour of the plant may cause some people to feel sleepy[].
The wood is brittle, and branches are very liable to break off in strong winds[].
The trees coppice readily[].
Yields of 20 cubic metres of wood per hectare can be obtained from this tree[].
The leaves were once used as a food for silkworms[], but were found to be unsuitable[].
This species is notably resistant to honey fungus[, ].
The trees are usually dioecious, though exceptions occur. Male and female forms generally need to be grown if seed is required[].

Edible Uses

Leaves - cooked[]. Used as an emergency food in times of scarcity, they have an offensive odour[, , ]. Some caution is advised, see the notes above on toxicity.

Medicinal

The tree of heaven is not often used in Western herbal medicine, though it is more popular in the Orient. Various parts of the plant are used, though the bark is the part most commonly used - however, it contains a glycoside that has not been fully researched and so should be used with caution[]. It needs to be used under the supervision of a qualified practitioner since the bark readily causes vomiting[].

The root and stem bark are antispasmodic, astringent, bitter, cardiac depressant, diuretic, emetic, febrifuge, rubefacient and vermifuge[, , , , , , ]. The vermifuge properties do not act on round worms or earthworms[]. A nauseatingly bitter herb, it is used internally to treat malaria and fevers, it also slows the heart rate and relaxes spasms[]. In China, the bark is a popular remedy for dysentery and other complaints of the bowels[]. In one clinical trial, 81 out of 82 patients were cured of dysentery when they were given this herb[].
A tincture of the root-bark has been used successfully in the treatment of cardiac palpitations, asthma and epilepsy[]. Tree-of-heaven is a folk remedy for asthma, cancer, diarrhoea, dysentery, dysmenorrhoea, dysuria, ejaculation (premature), epilepsy, eruption, fever, gonorrhoea, haematochezia, leucorrhoea, malaria, metrorrhagia, sores, spasms, spermatorrhoea, stomachic, tumours of the breast (China), and wet dreams[].
The bark is harvested in the spring and dried for later use[].

The leaves, bark of the trunk, and roots are put into a wash to treat parasitic ulcers, itch, and eruptions[].

In Korea, the root bark is used in the treatment of coughs, gastric and intestinal upsets[].

The stembark is emmenagogue[].

The leaves are anthelmintic, astringent and deobstruent[].

The fruit is used in the treatment of bloody stools and dysentery[, ]. They have also been used to treat ophthalmic diseases[].

The tree is used in homeopathic remedies for cancer[].

A resin extracted from the roots and leaves is a revulsive or vesicant[].

Extracts from the plant have been shown to be bactericidal[].

Agroforestry Uses:

When plants are put into marshy areas they drain the soil and thereby remove mosquito breeding sites[].
The plants have extensive root systems and sucker freely, they can be used in soil-stabilization programmes[]. Since the plant is tolerant of soil pollution it can also be used in land reclamation schemes on old mine tips etc[].
Plants can be grown as a tall hedge[].

Other Uses

A yellow dye is obtained from the leaves[].

The leaves contain 12% tannin, quercetin, as well as isoquercetin, and the alkaloid linuthine[, ].

The leaves and wood are high in cellulose and are used in paper-making[, ].

The crushed leaves and flowers are insect-repellent[]. The plant parts, especially the bark and leaves, when steeped in water, are said to yield an insecticidal solution[, ]. An aqueous extract of the leaves contains a substance that is toxic to other tree seedlings[].

The heartwood is creamy-white to light brown in colour. The wood is fairly hard, heavy, difficult to split, not durable, coarse grained. It is difficult to split but easy to work and polish. Though little used, except in poorer countries, the wood is suitable for cabinetry, cellulose manufacture, furniture, lumber, pulp, and woodwork[, , , , ].
The wood is also used locally for charcoal and firewood[, , , , , ].

Propagation

Seed - best sown outdoors as soon as it is ripe[]. If you only have a small quantity of seed it will probably be better to sow it in a cold frame. The germination can be poor[], averaging about 56%[], though one kilo of seed will normally produce in the region of 6,500 usable plants[]. The seed germinates best if given a short cold stratification of 8 weeks[, ]. The seed is not usually produced in Britain[]. Prick out the seedlings into individual pots when they are large enough to handle, keep them in a cold frame for their first winter and plant them out in late spring[].
Root cuttings in December[].
Suckers, planted out in late winter.