Tree of Heaven: Invasive Menace
The author is a Senior at Bellevue East High School in Bellevue, Nebraska, and a Director for YEPT.
In Bellevue, Nebraska, a deceptive invasive species is creeping up on every corner. It is called the Tree of Heaven, and it smells like old Taco Bell.
“One of the ways that we identify it… is the smell test,” Michelle Foss, Director of Operations at Fontenelle Forest, said. “So you can tear off a leaf and it smells really bad… somebody recently told us that it smelled like Taco Bell that's been sitting out too long.”
The Tree of Heaven, whose scientific name is Ailanthus altissima, looks similar to native trees such as black walnut and sumac. However, the Tree of Heaven was introduced from China in the 1700s for a variety of reasons, including shade and ornamental purposes. Its quick-growing tendencies allow it to rapidly gain a presence in cities like Bellevue.
The invasive Tree of Heaven can be found all over the city of Bellevue, including this tree on Bellevue Boulevard South. The Tree of Heaven is quick to reproduce, and it releases chemicals into the soil that harm other plants. "Tree of Heaven outcompetes the native plants," Michelle Foss, Director of Operations at Fontenelle Forest, said. "It also causes harm to the infrastructure around it." Photo by Victoria Bogatz
“There's Tree of Heaven pretty much everywhere,” Foss said. “It's in people's yards. It's in plenty of the roadway right-of-ways. It's in city parks.”
The tree can be recognized by its long leaves with dozens of leaflets, as well as the clusters of seeds found on female trees. One of the Tree of Heaven’s most recognizable characteristics is its intense smell.
“We’ve heard it described as like rotting peanut butter… so, yeah, it's not a pleasant smell,” Foss said.
The Tree of Heaven is considered an invasive species, meaning it is not native to an area and causes harm to the ecosystem. For 18% of U.S. endangered or threatened species, invasives are the main cause of their decline, according to the U.S. Forest Service.
“When you have a system that has been changed by people in general, you're going to have invasives,” Foss said. “When that balance is upset… you get invasive species that are filling those niches.”
Because the Tree of Heaven is an invasive species, it outcompetes native plants for resources and releases chemicals that prevent growth of nearby species, according to the USDA. Tree of Heaven can also have negative effects on infrastructure, such as by damaging house foundations.
“They grow tall, and they produce a lot of shadow that overcomes the smaller trees around, and eventually forcing them out, killing them off,” said Bob Cole, secretary and treasurer of the Avian Forest Homeowners Association.
Cole first learned about the Tree of Heaven from Ruth Richter, an Avian Forest resident and the president of local environmental organization Green Bellevue. Richter lives next to a forested lot inhabited by Tree of Heaven. After the plants began to move into her yard, she brought up the issue at a Homeowners Association meeting.
“We did some research to find out how you can control them,” Cole said. “The triclopyr is the name of the agent that will kill them off, but you have to mix it with diesel fuel.”
Cole, along with around ten other volunteers, decided to address the Tree of Heaven. They hit the invasive trees with a hatchet and sprayed the triclopyr-diesel fuel mixture into the cuts. However, he warned that being too aggressive with the triclopyr can alert the tree to a threat and cause it to reproduce even further.
“And you got to make sure that you don't totally encircle the bark on the trunk, because the tree will recognize that it's being attacked,” Cole said. “Otherwise, the tree will recognize that it's being attacked and then we'll start setting runners out and it just multiplies the problem.”
Foss recommends this technique for mature trees, but points out that younger trees can be pulled without harm.
“If the plant is very small, like really, really tiny, and it's just a couple of inches high, you could pull it,” Foss said. “If it is already a tree, then the best way to treat it is with herbicide.”
Mature trees often require years of repeated treatment to truly be eradicated. According to Iowa State University, Tree of Heaven that has been chemically treated should be monitored to ensure that seedlings and root sprouts are not present.
“In general, we have to hit our invasives with multiple things repeatedly to try to deplete those root reserves,” Foss said, “because just one time and just one thing is not going to do it. You have to keep hitting things multiple years and multiple seasons.”
Even then, sometimes the trees remain difficult to control. Don Preister, member of the Bellevue City Council and the Bellevue Tree Board, was part of an effort to treat Tree of Heaven with triclopyr in Jewel Park and near Wake Robin Elementary School. However, the trees continued to reproduce.
“We did find we were killing the trees. But all around them, the roots were sending up more runners, more new young trees,” Preister said. “We followed all the procedures that we knew about through Fontenelle Forest and through the state forest system, and we just were not successful.”
Preister and the Bellevue Tree Board eventually stopped their work around five years ago, saying the Tree of Heaven came back stronger every year. Other groups that have continued to treat the Tree of Heaven, such as Fontenelle Forest and the Avian Forest neighborhood, recognize the difficulty involved while maintaining hope.
“I'm glad that it's gaining interest again,” Foss said. “So hopefully there's something that can be done, but it's tough.”
Tree of Heaven: Invasive Menace © 2025 by Youth Environmental Press Team is licensed under CC BY-NC-ND 4.0.To view a copy of this license, visit https://creativecommons.org/licenses/by-nc-nd/4.0/
