How to Get Rid of Tree of Heaven—an Invasive Nuisance That Spotted Lanternflies Love

The tree of heaven (Ailanthus altissima) is a fast-growing tree species that is considered invasive in the United States. Native to China, Korea, and Taiwan, the tree of heaven was introduced to the U.S. in the late 1700s as an ornamental shade tree. It was planted widely throughout the country because it is fast-growing and tolerant of poor soils, pollution, and drought.

However, we now know that this tree can be harmful to native ecosystems and human structures. The tree of heaven also has roots that release chemicals that prevent other vegetation from growing, and it serves as a host for the spotted lanternfly. While this tree can be hard to eliminate, it’s not impossible. To help, we spoke to gardening experts who shared their tips for getting rid of the tree of heaven. 

How to Identify Tree of Heaven

Identifying the tree of heaven is the first step towards getting rid of it from your landscape. According to Mark Canney, urban forester with Arbor Day Foundation and detector of landscape at Arbor Day Farm, these are the key characteristics of the tree of heaven. 

• Size: Tree of heaven is a fast-growing tree that can reach up to 60 to 80 feet tall and up to 6 feet in diameter. 
• Leaves: Tree of heaven leaves are pinnately compound, meaning there will be a leaf with many leaflets attached to either side in opposite pairs. One leaf can grow up to 4 feet long and have 10 to 40 leaflets. The leaflets are lance-shaped with smooth margins. At the base of each leaflet are one to two bulbs called granular teeth.
• Smell: When the leaves are crushed, they emit a strong odor, often described as rancid, similar to burnt peanut butter or cat urine.
• Bark: The bark of this tree is smooth and brownish green when it’s young. As it matures, it turns light brown to gray.
• Seeds: The tree of heaven produces 1- to 2-inch-long winged seeds called samaras. The seeds are papery and grow in clusters, typically staying on the tree through winter.  

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How to Get Rid of Tree of Heaven

Getting rid of the tree of heaven is difficult because cutting it causes it to fight back even more. Canney says that eradicating this invasive species usually requires a combination of mechanical and chemical methods done carefully and consistently. He notes that late summer to early fall is the best time to remove the tree of heaven, as this is when the tree is moving nutrients down to its roots. 

1. Cut the tree down: Cut the tree down as close to the base as you can get, then immediately apply an herbicide, such as glyphosate or triclopyr, onto the stump to prevent it from re-growing. 
2. Apply an herbicide: After the main trees are treated, Canney advises monitoring for sprouts. Cut the sprouts and treat them with an herbicide as they appear. Be patient, as it can take several seasons to exhaust the root system.
3. Check for seedlings: Check the surrounding area for small seedlings with shallow roots. Hand-pull the seedlings, ensuring the entire root is removed. “It is helpful to do this when the soil is moist to make sure you pull as much of the root system out as possible,” says Marissa Schuh, an educator at the University of Minnesota Extension. Leaving any part of the root behind will cause regrowth. 

Tree of Heaven vs. Sumac and Black Walnut Trees 

Tree of heaven is often mistaken for sumac (Rhus spp.) and black walnut trees (Juglans nigra). According to Canney, this is because they all have large, compound leaves with many leaflets. But if you look closely, there are some very notable differences between these species. 

Leaf Shape

One key distinction between the tree of heaven and its lookalikes is that its leaves have smooth edges, while black walnut and sumac trees have serrated or toothed edges. Another way to tell the difference between these trees is to look at the area where the leaves attach to the stem. “If you remove one of the compound leaves, look at where it was connected to the stem,” says Schuh. “For the tree of heaven, this spot will be heart-shaped.”

Fruits and Seeds

Also look at what seeds or fruits the tree produces. The tree of heaven yields clusters of papery winged seeds called samaras, while sumacs produce upright clusters of fuzzy, red, berry-like drupes that last into winter and black walnuts produce large, green, round walnut husks in late summer to fall, Canney notes. 

Smell

Perhaps the easiest way to tell the tree of heaven apart from sumac and black walnut trees is to crush one of its leaves and give it a smell. According to Schuh, if it’s a tree of heaven you’ll be met with a rancid smell. “Another name for the tree of heaven is stink tree,” she adds. 

How Tree of Heaven Spreads

The tree of heaven can spread in several different ways, adding to its invasiveness. Here’s how experts say it has made its way across the country since being introduced in the 18th century. 

Seed Dispersal

Female trees produce clusters of more than 300,000 seeds annually that can be carried long distances by the wind. Canney adds that the seeds can also disperse via water, traveling down rivers and streams and colonizing floodplains. Once they are dispersed, the seeds will germinate in poor soils, cracks in pavement, rail beds, or disturbed ground. 

Root Dispersal  

The tree of heaven has a big, spreading root system. This allows it to send up a new tree up to 50 feet from the parent, or to grow back from its stump if it is cut, Schuh notes. When the trunk is cut or damaged, Canney adds that the tree typically responds by sending up dozens of new shoots from its roots. “Over time, these sprouts form dense thickets that crowd out other plants,” he says. 

How to Control Tree of Heaven

Keep these tips from Canney in mind to prevent the tree of heaven from spreading. 

• Remove the seeds from female trees before they mature. 
• Treat stumps and roots properly to prevent suckering. Consult the label before applying any herbicides.
• Pull seedlings early before they get established.
• Plant native trees or grasses in the area to resist re-invasion.
• Monitor the area for seedlings and sprouts every year.