Invasive KS tree has ‘heaven’ in its name, but smells like rotten peanut butter
With spring well underway across Kansas, many people are spending more time outdoors sprucing their gardens and lawns. That makes it a critical time to educate yourself on what you may be planting or pruning — especially non-native and invasive plant varieties.
By definition, invasive plants are species that cause harm to the environment they’re growing in, whether that be economic harm, environmental harm or harm to human health, according to Matthew McKernan with the Sedgwick County Extension Office.
“Oftentimes these invasive species can either produce large quantities of seeds, and those seeds are often quickly distributed by either things like birds, the wind or, sometimes unknowingly, by humans,” McKernan said.
That doesn’t mean all non-native plants are invasive, however, McKernan said. In fact, some non-native plants have become staples to the Kansas landscape. This includes shrubs like lilac and magnolia, as well as trees like the red maple and crabapples.
According to the Nature Conservancy, invasive plants have been a contributing factor to the decline of 42% of threatened or endangered species across the country.
“Many of these invasive species have adapted to thrive in disturbed soils — maybe where other plants naturally can’t grow as well — so they’re able to take advantage of space in the landscape that’s not ideal for growing other plants. They can easily establish in those areas and take off from there,” McKernan continued.
Commonly spotted invasive plants in Kansas include several types of honeysuckles and the infamous Callery (or Bradford) pear trees — which will be banned from sale or planting in the state in less than two years.
But there’s another invasive species with an interesting smell to avoid, according to McKernan.
The tree of heaven, scientific name Ailanthus altissima, is usually a smaller-sized tree that can reach up to 80 feet high in some cases. Native to China, the plant has become an invasive species widely spread across North America, including Kansas.
The tree reproduces quickly and can kill native plants around it. It also produces a large amount of seeds and releases a chemical into the nearby soil that is dangerous to the plants that is growing around it.
“When you get one plant, it sends out roots and suckers and then become kind of a mini forest ... that is also sort of problematic in the landscape,” McKernan said.
In Wichita, the tree of heaven is usually found in small wooded areas, vacant lots and suburban forested areas, McKernan said. But if you’re worried about accidentally planting it in your yard, you won’t find it at any plant shops.
“It’s not one that’s usually found in the commercial industry, like the horticulture trade, but it is one that is out there and can can take over large sections of land if it’s left unchecked,” McKernan said.
And there’s one really unique thing about it.
“When you crush the leaves or any of the plant parts, it kind of smells like a rotten peanut butter, [or] a rancid peanut butter smell,” McKernan said.
How to manage invasive plants on you Kansas property
If you’re worried your yard or land may be home to unwanted invasive plants, the first step is a survey to identify the culprits.
“The process starts out with education and understanding what plants to look for, so that as they do pop up in the landscape, you can identify them quickly and really eradicate them or limit their growth before they get large and really become a problem,” McKernan said.
Managing invasive plants depend on the age and type of plant.
“Sometimes it can be as simple as digging up or pulling the plant. But the larger those plants get, and the more time they spend establishing in the landscape, the more difficult control becomes,” McKernan said.
Once invasive plants become well-established, oftentimes people have to switch to chemicals for removal.
“You have to take to methods where you can actually control the underground roots so that you kill the entire plant,” McKernan said.
If you catch the plant early enough, removal can be an easy process.
“[Honeysuckle plants] pull very easily when they’re first established in the landscape, really up to their first year. They’re pretty easy to just hand pull, especially when the soil is wet,” McKernan said. “But once they’ve gotten six feet tall, hand pulling [isn’t] as effective.”
It’s the same for invasives like the tree of heaven.
“Once you’ve got a large tree established in the landscape, you’re talking about having to use chainsaws and deal with large amounts of wood, and then likely having to do some kind of cut stump treatment,” McKernan said.
For those who need help with invasive plants, the Sedgwick County Noxious Weed Department can help with any questions regarding invasive species removal. The Kansas Forest Service is also heavily involved with educating the public on invasive species and assisting with removal.
This story was originally published April 4, 2025 at 5:30 AM.
