Tree-of-Heaven
Ailanthus altissima
Washington State Classification
Class C — Widespread, County-Selected Control
Tree-of-heaven is naturalized throughout Washington.
Quick Reference
Identification
Growth Habit
It is a deciduous tree that grows to heights 60 feet (though sometimes larger). Trees have compound, alternate leaves and clusters of male or female flowers. Plant parts have a distinct pungent peanut-butter or popcorn smell.
Leaves
Leaves are alternate and compound, made up of 10-27 (sometime up to 45) leaflets. Leaflets with smooth edges except few rounded teeth at with large gland on underside. Terminal leaflets may have 1-2 enlarged lobes. Leaf petioles 2.75 to 5.1 inches long.
Flowers
Male and female flowers are in clusters on separate trees. Clusters are terminal (at stem tips) and are larger when having male flowers. Flower clusters may be up to 12 inches wide. Flowers are light green to yellow and small, about 1/4 to 1/3 inch wide.
Fruit & Seeds
Fruit is a samara—a single seed, centrally placed in a papery wing that is loosely twisted. Size ranges from around 1.5 to 2 inches long by 0.4 to 0.6 inch wide. The color at maturity varies from greenish yellow to reddish brown.
Impact
Tree-of-heaven is naturalized throughout Washington. It is a fast growing tree, forming thickets that outcompete native plants. It leaches a variety of allelochemicals into the soil that have demonstrated inhibitory or toxic effects on neighboring plants. It is also noted as being a preferred host for the spotted lanternfly, an insect that could damage many crops in Washington if it were able to establish here. Scroll down to find information about this invasive insect.
Ecology & Spread
Habitat
It grows in a variety of habitats, from open sites into more shaded areas by vegetative growth. It can commonly be found along forest edges, woodlands, fence rows, roadsides, railroad embankments, old fields, and urban parks. Click here to see a county level distribution map of tree-of-heaven in Washington. Please note, we are currently looking for distribution information on tree-of-heaven to help strategize control efforts due to the potential introduction of spotted lanternfly. Report locations of tree-of-heaven by:
Spread Mechanisms
Reproduction
Plants can reproduce by seed as well as vegetatively by roots and stump sprouts. Cut branches and trees can also form roots when left on moist ground.
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