Tree of heaven

Profile

Family

Simaroubaceae

Habit

Tree

Height

22.5 m

Spread

15 m

Growth

very fast

Lifespan

125 years

First yield

after 4 years

Hardiness

zone 6–9

Shade tolerance

partial shade

Soil

Sand, Silt, Loam

Soil moisture

very dry – near water

pH

4.1 – 8

Flowering & harvest

Times apply to the northern hemisphere in a temperate climate and shift with altitude and cultivar.

Uses

Edible: The tree's leaves are poisonous and serve as food for silkworms and snails. The tree's flowers are used by tree of heaven bees to produce a special honey.

Medicinal: The plant's root and stem bark possess astringent, bitter, and antispasmodic qualities. However, when taken in doses of 4-9g, it can be harmful. Traditionally, it is used to address malaria, fever, dysentery, intestinal issues, and worm infestations. A root tincture may alleviate palpitations, asthma, epilepsy, and gastrointestinal problems. The plant's fruit is utilized for bloody stools or urine, venereal diseases like metrorrhagia, dysmenorrhea, leukorrhea, gonorrhea, and spermatorrhea, as well as eye ailments. The leaves, bark, and roots of the plant can assist with parasitic ulcers, itching, and rashes. The leaves exhibit anthelmintic, astringent, and purgative properties.

Other uses: Leaves are yellow. Combining leaves with wood creates paper. A mixture of leaves and flowers, mashed and mixed with water, serves as an insect repellent. Wood is hard, heavy, splits easily, is easy to work, is not durable, and has a coarse grain. Carpentry uses wood. Charcoal and firewood are other products made from wood.

Growing

A highly resilient and low-maintenance tree, the tree of heaven can thrive in diverse conditions, being resistant to various diseases and able to withstand alkalinity, drought, frost, heat, pollution, and different soil types. It prefers lightly moist soil and a sheltered location, thriving best in sunny or partially shaded areas. The tree can endure annual rainfall ranging from 30 to 250 cm (with up to an 8-month dry season), average temperatures of 10° to 20°C, and soil pH levels of 5.5 to 8.0. It adapts well to urban spaces, landfills, and various soil types, except for calcareous or compacted clay soils. With a tolerance to temperatures as low as -15°C, the tree is visually appealing, resembling a tropical plant, and grows rapidly in its early stages, although its lifespan is relatively short. It spreads quickly through root sprouts, becoming a nuisance weed in some regions. The plant's roots are aggressive and can damage drainage systems. Male flowers and crushed leaves emit an unpleasant odor, potentially causing drowsiness in some individuals. The tree's wood, although occasionally cultivated, is brittle and prone to breakage in windy conditions, with the tree easily resprouting. While the leaves were once used as silkworm food, they were found to be unsuitable. Notably, this tree species shows remarkable resistance to the honey fungus. To obtain seeds, both male and female trees must be cultivated.

Propagation

Seeds should be planted outside immediately after they are fully developed. If you have a limited quantity of seeds, it's advisable to plant them in a cool greenhouse. Germination rates may be low, typically averaging 56%, but one kilogram of seeds typically yields about 6,500 viable plants. For optimal germination, seeds should undergo a brief cold stratification period of 8 weeks. Root pruning should be done in December, while planting the runners is recommended in late winter. Once the seedlings are large enough to handle, transfer them to individual pots, keep them in a cool greenhouse during the first winter, and then plant them outdoors in late spring.

Notable

Special features: highly drought/salt/pollution tolerant with a wide, shallow root system: good for soil stabilization and reclaiming (mines and ruins); breaks through concrete and water pipes!; min. 9°C Øyear; 1-2m growth/year; in swampy areas, for soil drainage → mosquitoes; reappeared in Germany in 1780 (Ice Age), banned from trade since 2019.

Origin & habitat

In spring, vibrant flowers blanket the mountain slopes, providing a stunning sight. The crisp mountain air and pure streams establish a delightful ambiance, perfect for hiking and unwinding.

Native to temperate to subtropical regions with moist, often calcareous soils. Prefers open habitats such as forest edges, disturbed sites, roadsides, and wastelands. Thrives in full sun but can also grow in partial shade. Found from lowlands to moderate elevations. Commonly colonizes disturbed areas and tolerates dry to moderately moist soils, showing adaptability to a wide range of soil types and pH levels.