Introduction

This non-native deciduous tree will rapidly grow to 70 to 100 feet in height and produces an open canopy of stout branches covered with one- to three-foot-long, pinnately compound, dark green leaves. Broken stems smell of rancid peanut butter, and males reportedly smell worse than female trees. The leaves turn only slightly yellow in fall before dropping. The small, green, male and female flowers are produced on separate trees and appear in dense, terminal clusters. The 1.5-inch-long, yellow to red/brown, winged fruits that follow the blossoms will persist on the tree in dense clusters throughout the fall and into the winter months, and are quite attractive. They can create a crunchy mess when they fall to the ground. Seeds sprout easily and seedlings usually invade surrounding land.

General Information

Scientific name: Ailanthus altissima

Pronunciation: ay-LANTH-us al-TISS-sim-muh

Common name(s): Tree-of-heaven

Family: Simaroubaceae

USDA hardiness zones: 5A through 8A (Fig. 2)

Origin: not native to North America

Invasive potential: invasive non-native

Uses: reclamation

Availability: not native to North America

Description

Height: 60 to 75 feet

Spread: 35 to 50 feet

Crown uniformity: irregular

Crown shape: upright/erect

Crown density: open

Growth rate: fast

Texture: coarse

Foliage

Leaf arrangement: alternate (Fig. 3)

Leaf type: even-pinnately compound

Leaf margin: ciliate

Leaf shape: ovate

Leaf venation: pinnate

Leaf type and persistence: deciduous

Leaf blade length: 2 to 4 inches, 4 to 8 inches

Leaf color: green

Fall color: no color change

Fall characteristic: not showy

Flower

Flower color: green

Flower characteristics: showy

Fruit

Fruit shape: elongated

Fruit length: 1 to 3 inches

Fruit covering: dry or hard

Fruit color: orange, yellow

Fruit characteristics: does not attract wildlife; showy; fruit/leaves a litter problem

Trunk and Branches

Trunk/bark/branches: branches don't droop; not showy; typically one trunk; thorns

Pruning requirement: needed for strong structure

Breakage: susceptible to breakage

Current year twig color: brown, reddish

Current year twig thickness: very thick

Wood specific gravity: unknown

Culture

Light requirement: full sun, partial sun or partial shade

Soil tolerances: clay; sand; loam; alkaline; acidic; occasionally wet; well-drained

Drought tolerance: high

Aerosol salt tolerance: moderate

Other

Roots: can form large surface roots

Winter interest: yes

Outstanding tree: no

Ozone sensitivity: sensitive

Verticillium wilt susceptibility: susceptible

Pest resistance: resistant to pests/diseases

Use and Management

Tree-of-heaven performs best in full sun on well drained, moist soil, but this is a tree that will survive almost anywhere, under any cultural conditions—smoke, dust, hot, cold, wet, or dry. It has been known to appear in cracks of pavement or even trash piles, and it will survive where no other trees will grow. Spreading rapidly by seed and suckers, tree-of-heaven is viewed by many as a pest- and weed-tree. But if well cared for, this tree can persist for a long time. Large specimens are known to grow trunks up to five feet in diameter.

Propagation is by seed and suckers.

Pests

No pests are of major concern.

Diseases

No diseases are of major concern, except for verticillium wilt.