Some Tips on Identifying the Tree of Heaven
Tree-of-Heaven (Ailanthus altissima) is a common invasive plant first introduced in the late 1700’s as an ornamental tree in the Philadelphia/Baltimore/Washington DC area. This fast growing tree is native to China and the far-and-away favorite of the Spotted Lanternfly.
Ailanthus can grow in a wide variety of areas but is especially common along road sides and other “waste areas” such as vacant lots. You may also find Ailanthus in any previously disturbed area which is reverting back to a wild state.
Tree-of-Heaven typically grows in single-sex colonies (all trees within the colony are male or female) and once established, a single tree can quickly over take an area through “sucker sprouts” emerging from the expansive root system. This tree also produces allelopathic chemicals in the roots and leaves which hinder native vegetation growth. The females are prolific producers of seed and a female tree as young as two years old may produce seeds.
Below are some pictures to help you identify Tree-of-Heaven on your property. It is important to distinguish between Ailanthus and several native “look-a-likes” such as Sumac and Black Walnut – both of which are very important trees to native wildlife.
Pinnately compound, 1-4’ long with 10-40 leaflets arranged opposite each other along a central stem. When crushed, leaves produce an offensive odor.
When young the bark appears smooth with a faint greenish cast. As the tree matures the bark begins to resemble the skin of a cantaloupe.
Clusters of samaras (wings) on the female Tree-of-Heaven are about 1-2” long and somewhat twisted. The clusters may continue to hang on the tree through out winter.
Control of Ailanthus is very difficult due to the extensive root system which is able to quickly replace any trees that are simply cut down. In fact, removing one tree could produce hundreds more! Treating with a herbicide to kill the root system first and cutting afterwards is the best course of action is best left to a professional tree service. For more information on controlling Tree-of-Heaven visit extension.psu.edu