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Invasive Tree of Heaven (Ailanthus altissima) is a rapidly growing deciduous tree that has become a widespread invasive species across North America. Also known as stinking sumac or Chinese sumac, it was introduced to the United States as a horticultural specimen and shade tree. Rapid growth and abundant seeds allow it to spread aggressively to create dense thickets that displace native vegetation. It also secretes a chemical into the soil that is toxic to surrounding plants. Its aggressive root system can also damage pavement, sewers, wells and building foundations. 
 
Tree of Heaven is the preferred food source (host plant) of the Spotted lanternfly (SLF), a destructive, sap-feeding planthopper. SLF is a relatively new plant pest to the United States, but populations have increased rapidly. It is now found across Connecticut and is widespread in Fairfield and New Haven counties.
A pretty, distinctive insect, adults are about one inch long and a half-inch wide. Their forewings are tan with black spots. Hindwings, noticeable when wings are spread, are colorful red and black patches separated by a white patch. Adults are active from July to November and will crawl, jump or fly short distances. 

While Tree of Heaven is the SLF’s preferred food source, it also feeds on economically important plants including grapevines, ornamentals and native trees such as maple, black walnut, birch and willow. Feeding damage significantly stresses plants, impacting health with potential for causing death. To protect property and trees, The Connecticut Agricultural Experiment Station says the best thing a homeowner can do to  is rid their property of Tree of Heaven, so as not to attract the SLF.

How to Identify Tree of Heaven
It is important to correctly identify the Tree of Heaven.  On first glance, it appears similar to some native trees and shrubs that also have leaves arranged in pairs along a plant’s stem (staghorn sumac, hickory and black walnut). Tree of Heaven is distinguished by a notch at the base of each leaf, fuzzy, reddish-brown twigs and clusters of light green seed pods. If all else fails, there is the unmistakably strong, offensive smell of its flowers, leaves and stems when crushed that resembles burnt peanut butter.
  
Controlling Tree of Heaven
According to Penn State Extension, cutting alone will not reduce Tree of Heaven’s  ability to spread, in fact, it will likely make it worse. Pulling it out can also activate the root system, causing it to send up more shoots to create new trees.
 
The best method is to target the roots with a systemic herbicide applied mid-to-late summer until onset of fall color when the tree is moving carbohydrates to the roots. Herbicides can be applied to foliage, bark or cuts on the stem, also known as “hack and squirt.”
 
However, cut stump herbicide applications do not prevent root suckering and should not be utilized. Herbicide applications made outside this late growing season window will only injure above-ground growth. As always, employing the help of a professional licensed pesticide applicator is recommended.
 
For more information, go to Penn State Extension and search: tree of heaven control strategies. Local arborist Mike Switser of North Country LLC, has the expertise in proper management.