4 min readThe tree of heaven (Ailanthus altissima) may be one of the most ironically named plants in the entire plant kingdom. Far from being a heavenly entity, its presence on your property could signal pests, ecological distress, and even damage to pipes, if it’s close enough to a building.
As with many other invasive plants, you’ll want to be careful with how you get rid of it—cutting this tree down will only make things worse. For that reason, we tapped two experts to explain exactly how to deal with a tree of heaven in your backyard and (hopefully) prevent it from returning.
What Is a Tree of Heaven?
The tree of heaven is native to China and is considered to be the most invasive tree in America. In fact, as Logan Foltz, certified arborist at Urban Arborists, says, the tree “outcompetes” many of our North American trees in their natural habitats and is “notoriously challenging” to control. It’s also extremely fast-growing (up to 15 feet in the first year) and very resilient.
“The tree of heaven’s ability to thrive in many different climates and locations is what led it to rapidly spread from the East Coast gardens of Philadelphia to the California coast,” explains horticulturist and organic farmer Nathan Heinrich.
The plant can be identified by its slim but sturdy trunk and branches, and its uniform, fern-like fronds that are distinguished by having “glandular teeth” at the base of each leaf. Female varieties of the plant will have red, yellow, or green seed clusters. Note that native, non-threatening black walnut trees and some varieties of sumac also possess similar physical characteristics to trees of heaven, so always be sure you know which plant you’re dealing with.
Why Are These Trees Undesirable?
The tree of heaven has been labeled as invasive because of its ability to produce up to thousands of seeds every year. These seeds can germinate in almost any condition, from sidewalk cracks to gutters to your very own garden. The tree’s root system, which can spread out as much as 50 feet from the trunk, can even infiltrate and crack hardscaping and pipes as it seeks out sources of water. And it’ll choke out neighboring plants.
“If the root system is damaged or the trunk is cut, the tree will respond by sending up suckers from the roots that will grow into new full-size trees,” Foltz says.
They’re considered very nearly “unkillable” because, as Heinrich explains, the tree of heaven has “virtually no natural enemies, drought tolerance, rapid reproduction, and the ability to resurrect by resprouting after being cut down.”
If that weren’t bad enough, trees of heaven are also a host plant for the equally invasive and destructive spotted lanternfly, according to the U.S. Department of Agriculture. Lanternflies, another species without a natural predator in the U.S., suck the sap out of trees and vulnerable plants and can spread plantborne diseases.
The Best Way to Get Rid of a Tree of Heaven
Although they’re virtually indestructible, there are some ways experts approach these tough-to-kill trees. Calling this an “old-school approach,” Foltz believes that the best way to get rid of a tree of heaven is to cut the tree down to its base, drill the remaining stump full of holes, then fill those holes with rock salt.
“This method slowly desiccates the stump and connected root system, stopping the tree of heaven from resprouting,” Foltz says. “The drawback here is that the rock salt will make the soil inhospitable for new plantings.” So, this method may be better used for areas of your property where you’re not trying to grow anything.
Heinrich agrees with this method, saying that it’s best to do this in July and August. As an alternative to using rock salt, he recommends injecting multiple rounds of herbicide into the drilled holes and slits in the stump.
He adds that another way to potentially eradicate a tree of heaven is to exhaust its energy reserves by repeatedly cutting it back until its roots can no longer sustain growth.
Should You Ever Leave a Tree of Heaven Alone?
Trees of heaven are a menacing presence, but is it necessary to get rid of them? Foltz says that it depends.
“These trees are not inherently evil—they are simply incredibly successful at what they do, which is to make more trees,” he notes. “While I do typically recommend removing the new trees as you see them sprout up, some mature specimens may be worth retaining. Consider the overall ecological impact of your tree, and assess whether a native planting would better serve the community.”
