Why is it a threat?
Because the tree of heaven is a prolific seed producer and grows rapidly, it successfully competes with native vegetation. Also, its tissues contain a compound called ailanthone that is toxic to many other plant species. Its root system is aggressive enough to cause damage to sewers and building foundations.
How did it get here?
A missionary returning from China mistakenly introduced the tree of heaven to the U.S. in the 1750s, believing its seeds to be those of the lacquer tree. During the California gold rush, Chinese miners brought seeds with them for uses in traditional medicines.
How does it spread?
Each tree can produce as many as 325,000 seeds per year, and the seeds are easily dispersed by the wind.
How can you remove it?
The most effective way to control tree of heaven is to pull seedlings by hand before the tap root develops.
What can you plant instead?
Many lovely native trees and shrubs make excellent alternatives. In the eastern U.S., for example, try deciduous shrubs such as staghorn sumac, smooth sumac, box elder, ash or black walnut. Be sure to check with your local nursery or plant society for recommendations that are native to your region.