Take just a short drive down the road or interstate, and I bet you will have a good chance of seeing tree-of-heaven (Ailanthus altissima). Over the last few years, I have really started to notice this tree along the sides of roads. I have also made numerous landowner visits where I have seen it on their property. It can be found throughout much of the continental U.S., as indicated by Figure 1. While it is native to Eastern China, it was introduced to the U.S. in 1784 from Europe as a unique, fast-growing ornamental. It can grow on a wide range of soil and site conditions, while tolerating poor growing conditions.
Tree-of-heaven is a rapidly growing tree that has the capability to form dense stands. It is also allelopathic, which means it creates a biochemical that can suppress the germination, growth, and survival of other plant species.
The tree can reach 80 feet in height and has long, pinnately compound leaves with circular glands (Figure 2) under the lobes of the leaflet bases. The leaves are alternate with 10 to 41 leaflets on 1 to 3-foot stalks (Figure 3). To me, the leaves resemble those of sumac and black walnut, except they can be much longer.
Tree-of-heaven flowers between April and June (Figure 4). Typically, you will see long terminal clusters of small yellowish-green flowers. The flowers produce a seed (Figure 5) that can stay on the tree from July to February, and this is where you can really notice the difference between tree-of-heaven and sumac (Figure 6). The seed is very prolific and can be spread by wind and water. Tree-of-heaven can also reproduce by root sprouts and resprouts profusely from cut stumps.
Recommended Control Procedures:
Tree-of-heaven has an extensive root system, making control with one application difficult. Treatment timing with a follow-up application may need to be made in the second year to control sprouts.
Large trees: Make stem injections and then apply Garlon 3A, Pathway*, Pathfinder II, or Arsenal AC* in dilutions and cut spacings specified on the herbicide label (midsummer best, late winter somewhat less effective). For felled trees, apply these herbicides to stem and stump tops immediately after cutting. However, stump treatment typically does not prevent root suckering.
Saplings: Apply Garlon 4 as a 20-percent solution in basal oil, vegetable oil, crop oil concentrate, diesel fuel, or kerosene (2.5 quarts per 3-gallon mix) or apply undiluted Pathfinder II to young bark as a basal spray.
Seedlings and saplings: Thoroughly wet all leaves with one of the following herbicides in water with a surfactant (July to October): Arsenal AC* as a 1-percent solution (4 ounces per 3-gallon mix), Krenite S as a 15-percent solution (3 pints per 3-gallon mix), Garlon 4 as a 2-percent solution (8 ounces per 3-gallon mix), or Escort XP* at 1 ounce per acre.
Prescriptions used from the Nonnative Invasive Plants of Southern Forest: A Field Guide for Identification and Control publication.
*Nontarget plants may be killed by root uptake
Author
Jeff Fellers, Cooperative Extension, Forestry and Wildlife Agent
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