Introduced, naturalised · Up to 28 m

Tree of heaven

Ailanthus altissima · Simaroubaceae

Tree of heaven is a tall town tree, especially common in London. Its huge leaves have a few big teeth at the base of each leaflet. Bruised, they smell foul.

Often mistaken for common ash. How to tell them apart →

Know it by

Leaves40 to 60 cm long, 11 to 21 leaflets in neat pairs.Twisted keysNarrow wings about 3 cm, seed central, in huge drooping bunches.

Leaf scarsTiny reddish domed buds on stout, finely velvety shoots.

Then check · BarkSmooth and dark grey even on a big trunk, streaked with fine pale lines running up it.

How to identify a tree of heaven

Leaves

40 to 60 cm long, with 11 to 21 leaflets in neat pairs, each with a few big teeth at its base.

Twisted keys

Narrow wings usually about 3 cm long, twisted at both ends with a seed in the middle, in huge drooping bunches.

Daniel Cahen, CC BY 4.0

Leaf scars

The shoots are stout and finely velvety, with tiny reddish domed buds, each above the big, pale, heart-shaped scar of a fallen leaf.

Learn the tree of heaven in TreelyEvery part through the year, and a short round each day until you know it.Get Treely

Every part, in photographs

Tree of heaven leaves: huge and feathered, big teeth at each leaflet base — LeavesHuge and feathered, big teeth at each leaflet base

Tree of heaven bark: dark grey, smooth, with fine pale vertical streaks — BarkDark grey, smooth, with fine pale vertical streaks

Tree of heaven leaf scars: tiny red buds over big heart-shaped scars — Leaf scarsTiny red buds over big heart-shaped scars

Mattia Menchetti, CC BY 4.0

ShapeShort trunk, stout twisting limbs, root shoots around it

When to look

JFMAMJJASOND

In leaf

Flowers

Twisted keys

In leaf: May to November · Flowers: June to July · Twisted keys: July to March

Every tree on the calendar · How to identify trees in winter

Where you’ll find it

Mostly planted, in streets, squares and parks, especially in London, and in gardens in other towns. It is frequent in warm parts of Britain and rare in the north. Wild ones, grown from seed, are turning up more and more in towns in south-east England.

What it’s mistaken for

Tree of heaven or common ash?Both are big trees with feathered leaves.Edge of a leaflet

Tree of heaven or false acacia?Both are big trees of warm towns with feathered leaves, and both send up shoots from their roots.Base of a leaflet

Tree of heaven or elder?Both have feathered leaves.Whole plant

WalnutBoth have big feathered leaves set singly along the shoot, and in winter their twigs look much alike. Leaf. Tree of heaven: 11 to 21, in neat pairs. Walnut: 5 to 13, most often 7.
RowanBoth have feathered leaves set singly along the shoot. Leaf. Tree of heaven: smooth, with a few big teeth at the base. Rowan: toothed to within 1 to 2 cm of the base.

In the app

There’s more of the tree of heaven in Treely

Every part, through the yearLeaves, bark, buds, flowers and fruit, photographed in every season
Its lookalikes, side by sideThe checks that settle it, part by part
A short round each dayUntil you know the tree of heaven on sight, from any side
Name it from a photoA leaf, the bark or a flower, and Treely tells you which tree

App Store Google Play

Free to download.

Every fact on this page is checked against the Collins Tree Guide, last in November 2026. Spotted something that looks wrong in front of a real tree? Tell us. How we check.

Photographs: Mattia Menchetti (CC BY 4.0), steve_mcwilliam (CC0), Daniel Cahen (CC BY 4.0), tomerler (CC0), Leon Cross (CC BY 4.0), bmapp02 (CC0), Michel Langeveld (CC BY 4.0). With thanks to everyone who shares their photographs on iNaturalist and Wikimedia Commons.