Identifying the Tree of Heaven
At first glance, the Tree of Heaven appears to resemble a number of other trees or shrubs. However, it possesses unique characteristics in its leaves, bark, seeds and scent which allow it to be easily distinguished. Be sure to positively identify this tree before applying control measures.
Bud: In early spring, just prior to leaf-out, the buds of the Tree of Heaven are fairly distinctive and orange-reddish in color. (Note the leaf scars also present in this photo.)
Compound Leaves: The leaves of a Tree of Heaven are known as compound leaves -- leaves consisting of leaflets. A single leaf may be 1 to 4 feet long with as many as 40 pointed leaflets.
Leaflet: At the base of each leaflet are one to two protruding bumps called glandular teeth. When crushed, leaflets and all plant parts will have an offensive odor described by some as “rancid peanut butter” and “a well-worn gym sock”.
Bark: During the winter months, bark and leaf scars are the best ways to identify Tree of Heaven. The bark can be light brown to grey, and smooth in young trees. In later years, the bark turns a darker grey and becomes rough. .
Leaf Scars: The leaf scars result from the tree dropping its leaves and are located where large leaves were attached to the branches. They are characteristically heart-shaped or shield-shaped.
Seed Clusters: A female tree can produce between 300,000 and 350,000 seeds each year. The seeds are twisted samaras, or wing-shaped, similar to maple seeds but only single-seeded, not dual samaras. They are clustered in large groups and can turn reddish or yellow as they mature..
Common Trees Misidentified as Tree of Heaven
Staghorn Sumac: While from a distance this tree might look similar to Tree of Heaven, there are many easy ways to tell them apart. The leaflets of the sumac are serrated or toothed while Tree-of-Heaven has almost entirely smooth leaflet edges. Tree-of-Heaven leaflets have one to two protruding bumps at the base, while the Sumac leaflets do not. If you crush a sumac leaf or small twig, it will not have the "rancid peanut butter" smell but a mild vegetative scent. The sumac also produces a cluster of edible red berries that ripen in the summer and persist throughout the winter.
Black Walnut: Like the Tree of Heaven, the Black Walnut has compound leaves, but the edges of leaflet are serrated, not smooth like the Tree of Heaven. The leaflets are also lacking the protruding bumps at the base of each leaflet, a distinguishing characteristic of Tree of Heaven leaflets. The bark of the Black Walnut is also markedly different: dark brown in color with a diamond-shaped pattern. Most notably, the fruit of the black walnut is a round nut covered with a brownish-green husk.
