For years, we have removed every buckthorn shrub that crept onto our property, but recently this invasive species has gotten out of hand.
This fall, we found several that were taller than us and loaded with deep blue berries. Knowing the ill effects buckthorn has on native northern Illinois landscapes, we quickly removed and disposed of it, while chiding ourselves on not staying ahead of its spread.
Though I write about buckthorn a lot, many folks still don’t know what it looks like or why it’s so harmful to the ecosystem. There is so much about buckthorn that makes it an inappropriate choice to plant anywhere in northern Illinois. Now is the perfect time to remove it, because it’s easy to find amongst most other trees and shrubs that have lost their leaves.
Buckthorn, which grows up to 25 feet tall and has 1-inch-long thorns, maintains its 3-inch-long, elliptical-shaped leaves into late fall and even early winter. Right now, many of them have produced ripe berries that attract wildlife.
Landscapers introduced buckthorn from Europe to use as a privacy hedge in the late 1800s, specifically because it stayed green in autumn and early winter, long after most other plants had lost their leaves.
Unfortunately, northern Illinois has the perfect climate to allow buckthorn to proliferate, and soon biologists learned how destructive it is to the native landscape. It grows easily in shade, crowding out the native plants, turning a diverse area into a thicket of just one species.
Buckthorn also has a shallow root system, causing erosion and runoff, that can pollute nearby waterways. Buckthorn leaf litter decomposes quickly, often leaving bare patches of soil. Salamanders, snakes and other reptiles and amphibians use leaf litter as a habitat. When an area is overtaken by buckthorn, they have no place to go. Neither do overwintering butterfly larvae and other insects.
In addition, a recent study in a Lake County forest preserve revealed that a chemical in buckthorn can harm amphibians, including salamanders and frogs.
It’s true that buckthorn produces copious berries, which provide food for wildlife. But science has shown the buckthorn berries do not provide the nutrition our native birds need. They’ve evolved with native plants, such as dogwood that produce more nutritious berries.
Birds also transfer the seeds to other places where new buckthorn plants begin growing with vigor. We had noticed a few years ago some migrating Tennessee warblers munching on buckthorn berries in our yard, and vowed to get rid of the buckthorn and replace it with something native.
But one of those berries got planted by a bird and more buckthorn plants began sprouting and producing berries. The key is to get rid of it before it produces berries, and to keep on cutting off any green sprouts.
Natural area land managers and volunteers have been removing buckthorn for decades in the region’s preserves. They treat the stumps with a type of herbicide that keeps the plant from re-sprouting. Natural area land managers can remove all the buckthorn they want, but if homeowners adjacent to those properties, as well as throughout the region don’t, birds will eat the berries, deposit the seeds back into the natural areas and start the cycle again.
The only problem for homeowners is that we would need a permit to get the herbicide to put onto the buckthorn stumps. So we must be diligent in cutting down all sprouts from shrubs before they grow and start producing berries. When we removed the buckthorn, there was quite a lot of bare space left, which we will replace with native shrubs.
Some suggestions include gray dogwood, American elderberry and staghorn sumac. We have planted nannyberry to replace non-native honeysuckles several years ago, and now the nannyberry is producing berries in autumn. We also have two stands of elderberry that attract robins and kingbirds.
Some folks have said to let nature take its course. If the buckthorn grows, then let it grow. But to me, the more bitter ecological pill to swallow would be what happens to the environment if buckthorn is allowed to proliferate.
Botanists have told me that not all plants that come from another country are wreaking havoc in our northern Illinois woodlands, and elsewhere for that matter. It’s maybe about 25%. Buckthorn is among that 25% that has really taken a toll on our native landscapes, and in turn on the native creatures that use those landscapes to thrive. (Stay tuned for information on some of the other big invasive plants, including teasel.)
When I walk in the neighborhood or even in a natural area, I can always find buckthorn somewhere. That makes it easy to be pessimistic about the 21st-century challenge to restore our native landscapes.
My optimism would soar if just one person reading this decided to learn to identify buckthorn, remove it from the yard and replace it with a native species. Let me know if you do.
Sheryl DeVore has worked as a full-time and freelance reporter, editor and photographer for the Chicago Tribune and its subsidiaries. She’s the author of several books on nature and the environment. Send story ideas and thoughts to sheryldevorewriter@gmail.com.
