Tree of Heaven (Ailanthus altissima) is known by a number of names - stinking sumac, Chinese sumac, varnishtree and stinktree. No matter what you call it, it still remains an invasive species in Indiana.
The tree of heaven is a rapidly growing deciduous tree with pale gray bark, light brown twigs and large pinnately compound leaves. It is native to China and was brought to the United States in the late 1700's as a horticultural specimen and shade tree. Its ease of establishment, rapid growth and absence of insect or disease problems made it popular when planning urban landscaping. Its ability to produce an overly abundant amount of seeds, reproduction through roots and a chemical that can prevent or kill other plants near it has made it a species that have many states - including our own - concerned.
Today this invasive tree threatens to overwhelm our natural areas, agricultural fields and roadsides. Established tree of heaven stands have been found in every county in Indiana and will continue to flourish unless we put a stop it first.
Controlling & Managing Tree of Heaven
Why should we be concerned about the tree of heaven? It is a prolific seed producer and can thrive in even the most unfavorable conditions with little management. Its rapid growth also means that it can crowd out nearby native plant species, and its aggressive root system can cause damage to pavement, sewers and building foundations.
Thankfully there are multiple ways to get rid of this invasive species. The most effective way to control tree of heaven is to pull seedlings by hand before the tap root develops. If the plant has matured, cutting alone will only help temporarily by reducing its ability to spread. For larger trees and stands, there are a variety of chemical methods that can be found at the Plant Conservation Alliance and Maryland Department of Natural Resources web pages.
Correct identification of tree-of-heaven is important. Several native trees and shrubs also have pinnately compound leaves such as sumac, ash and black walnut - all that could be confused with the tree-of-heaven. It can be distinguished from native species by its fuzzy, reddish brown twigs and red fuzzy fruits that stand erect. It also has quite a stench; the tree, particularly its flowers, it releases a strong, offensive smell.