Tree of Heaven
(Ailanthus altissima)
Rapidly-growing tree that can reach 80’ or more. Tree of heaven has smooth stems, pale gray bark and light brown twigs. Leaves and male flowers have a strong odor of rancid peanuts.
Overview
Other names for this plant include:- Common names: China sumac, stinktree, ailanthus
- Scientific names: A. glandulosa; Rhus cacodendron
- Aggressive invader of urban areas, fields, roadsides, fencerows, woodland edges and forest openings. It may occur as seedlings in recently planted fields.
- Prolific seed producer; once established can form an impenetrable thicket.
- Allelopathic; plant produces chemicals that are toxic to other organisms, both plants and insects.
Classification in Wisconsin: Restricted
Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for tree of heaven was based upon this literature review [PDF] developed by the department.
Identification
Leaves: Large, alternate, pinnately compound, 1-4’ long. Composed of 11-25 entire leaflets with the exception of 1 to several glandular teeth near the base.
Flowers: Small; yellow-green; 5-6 petals; borne in dense clusters near ends of upper branches in late spring; dioecious.
Fruits & seeds: Green turning pink to tan, papery, two-winged samaras in clusters. Develop in late summer to early fall and may remain on the tree through winter.
Roots: Aggressive; spreading rhizomes.
Similar species: Black walnut (Juglans nigra), butternut (Juglans cinerea), and some species of sumac (Rhus spp.). The leaf margins of the look-alikes have small teeth, with the exception of winged sumac, while those of the tree of heaven are smooth.
Control
Mechanical: Seedlings can be removed by hand. Trees may be cut at ground level with a saw, most effective when the tree has begun to flower. Re-sprouts may occur after treatment and successful control will require repeated cutting.
Chemical: Foliar spray with either glyphosate or triclopyr ester from June-September. Basal bark with triclopyr ester during the summer. Cut-stump treatment with triclopyr or glyphosate.
For more information on control techniques, visit the Tree-of-heaven factsheet [exit DNR] by University of Wisconsin-Extension.
Photos
View tree of heaven pictures in our photo gallery!
Resources
Sources for content:- Czarapata, Elizabeth; Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. University of Wisconsin Press. 2005. Pg. 87-88