Tree of Heaven Plant Care

Tree of Heaven (Ailanthus altissima) belongs to the Simaroubaceae family within the Ailanthus genus. Tree of Heaven is native to northeast, central China, and Taiwan. Tree of Heaven is also known as Chinese Sumac, Copaltree, Simaruba.

Tree of Heaven displays a fast-growing tree growth habit, reaching up to 50 ft tall with a spread of approximately 30 ft. Tree of Heaven produces small greenish-yellow flowers in large clusters.

Leaf size: approximately 12 inches.

Water a young or newly planted Tree of Heaven every 7–14 days, soaking the whole root zone, until it is established — usually one to two growing seasons. Established trees mainly need water during long dry spells. In a container, water whenever the top few centimetres of soil are dry.

Tree of Heaven thrives in full sun to partial shade.

Ailanthus altissima tolerates temperatures of 50–90°F. Tree of Heaven prefers humidity levels of 40–70%.

Well-draining loamy soil with added compost for nutrients. Good drainage is essential for Tree of Heaven to prevent waterlogging, which leads to root rot and fungal issues.

Feed Tree of Heaven every 6 months during the growing season with a balanced, slow-release fertilizer at the rate on the label. Established trees in good soil often need little extra feeding, so let weak growth or pale foliage guide you.

Stop feeding by late summer so new growth can harden before winter.

The PlantoScan app can remind you when to water and when to fertilize each plant.

Choose a spot with full sun to partial shade and well-draining loamy soil with added compost for nutrients. Avoid low spots where water collects after rain.

Tree of Heaven is suited to USDA Zone 3b – 9b.

Plant container-grown or balled-and-burlapped trees in spring or early autumn, setting the root flare at soil level, and water well after planting.

Tree of Heaven can spread to about 30 ft (9.1 m) and reach about 50 ft (15 m) tall. Space plants about 30 ft (9.1 m) apart so mature crowns don't crowd each other, and plant at least half that distance from buildings, fences and paths.

Planning a row or hedge? Try the tree spacing calculator.

Prune Tree of Heaven while it is dormant in late winter: first remove dead, damaged and crossing branches, then thin lightly for shape.

If it flowers in spring, prune right after flowering instead so you don't remove next year's buds. Never take off more than about a quarter of the tree in one year.

Tree of Heaven is hardy down to USDA zone 3b, so once established it can stay outdoors through winter in that zone and warmer ones.

Water deeply in late autumn before the ground freezes, and spread a 5–8 cm (2–3 in) layer of mulch over the root zone, keeping it away from the trunk.

Young and container-grown trees need extra protection: roots in a pot freeze much more easily than roots in the ground.

Tree of Heaven can be propagated through seeds, root cuttings. Similar propagation techniques also apply to chinese tree of heaven plant care, which shares the same genus.

See all plants toxic to cats and plants toxic to dogs.

Tree of Heaven is susceptible to ailanthus webworm, ailanthus defoliator. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.

Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.

Tree of Heaven grows outdoors in USDA Zone 3b – 9b. It survives winters down to planting zone 3b. Tree of Heaven is native to northeast, central China, and Taiwan.