Tree-of-heaven can make life hell
Rarely do you find such irony in nature.
This so-called Tree-of-heaven, with its invasive nature and pungent stench, makes life hell for some folks who have it growing in their landscape.
This tree, with its attractive, glossy leaves, is also called Chinese sumac and is a fast-growing, aggressive plant that can quickly take over your yard if you don’t pay attention. And there’s plenty of it growing around town, though it’s unlikely that many people who have it growing in their yard planted it intentionally.
This sumac is native to China and was introduced, like many other invasive species, as an ornamental plant. It also was valued as food for silkworms and as a medicinal plant for Chinese immigrants, according to the University of California-Davis, but it’s not considered a desirable plant, by any means.
This tree has a lot of secret weapons that helps it take over your yard. Because the tree tolerates poor soil conditions, it can grow quickly in areas where other plants can’t manage. It also doesn’t mind cracks in the sidewalk or disturbed soil, and secretes chemicals in the soil through its leaves, bark, roots and seeds that discourage other plants from growing.
The tree reproduces prolifically, and can quickly form dense stands of vegetation that choke out any other competing plants.
The USDA reports that a mature Tree-of-heaven can produce up to 300,000 seeds in a year, though it can also reproduce by sending out shoots under the soil. According to UC-Davis, new shoots can sprout up to 50 feet away from the host tree and those shoots can grow more than 3feet per year.
Tree-of-heaven’s leaves smell rather skunky if you crush them and can cause a rash in people with sensitive skin. Yet, this plant is not on the state’s list of noxious weeds, like others that have been targeted for removal, such as myrtle spurge and Russian knapweed. So that means you’re on your own, pretty much.
If you’re taking on a significant amount of Tree-of-heaven, you should plan for up to five years of a battle, in order to eliminate the seeds, the existing trees, and the roots that have spread and will sprout new trees.
The USDA recommends a plan of action that begins with preventing Tree-of-heaven from putting down roots in new areas. In other words, keep it out of places where it isn’t already growing. The next step is to treat smaller infestations, and then it’s key to tackle the bigger trees to prevent more seeds and roots from making more trees.
Hand-pulling is practical for very young seedlings, and digging up bigger seedlings is pretty easy. If you’re extracting a stump or roots, it’s important to make sure you’ve dug up every part of it, or sprouting will happen.
Once the trees get too big to dig out, your option is spraying the trees with herbicides. If the trees are mature, the recommended treatment is to cut the bark of the tree (also called girdling or drilling) so those chemicals can penetrate into the tree and kill it. The USDA recommends timing this treatment in June.
Another method is to apply herbicide to the leaves this time of year, before fall color sets in, while the tree is still growing.
If the trees aren’t too large, you can also use what’s called the “cut-stump” method, in which you cut the tree down and paint the stump with herbicides like triclopyr or dicamba before the tree has a chance to seal over the wound. That means applying herbicide to the cut surface within five minutes of cutting the tree down. Even after this application, you’ll need to monitor the area around the stump to make sure sprouts don’t pop up.
Whatever you do, don’t be fooled by this tree’s name. There’s nothing heavenly about it, and unless you want a yard full of stinky trees, you’ll want to plan your attack if it shows up.