Buckthorn is an invasive species that was imported from Europe as an ornamental shrub in the 19th century intended for creating privacy on properties. Since then it has spread throughout much of the Midwest in North America where it continues to outcompete native plants and disturb local ecosystems. Buckthorn:
- Grows extremely fast
- Has an extended growing season compared to native plants
- Berries are slightly toxic and act as a laxative when ingested by wildlife, which helps the plan spread spread easily
- Emits a chemical called “Emodin” into the ground, which is toxic for plants and animals
- Takes over forest floor and outcompetes smaller trees for light
- Contributes to erosion by decreasing biodiversity and soil health
- Lacks competition.
There are two main varieties of buckthorn found in North America: Common and Glossy. The two vary in in appearance, but are equally invasive and can grow up to 25 feet tall.
|Common Buckthorn||Glossy Buckthorn|
If you think you have buckthorn, the Minnesota DNR provides a more detailed buckthorn identification guide.
The best method for removing buckthorn depends on the size of the plants and how many you wish to remove.
For very small plants, hand-pulling or using an uprooting tool can be an effective solution. This works best on plants that are less than 3/8 of an inch in diameter. When using this method, it is important to uproot the plant.
When dealing with an infestation of buckthorn greater than two inches in diameter, the best method is to cut the buckthorn at ground level and chemically treat the stump. Treat the stump within two hours of cutting with glyphosate (Roundup) or triclopyr (Garlon 3A or Garlon 4). It is important to treat the stump because buckthorn will continue to grow from the same root system.
It is recommended to restore the ground’s seed bank after removing buckthorn. This can be done by planting a variety of native seeds over the newly exposed dirt. Buckthorn seeds can lay dormant in the ground for up to 10 years, so it is important to make sure that those seeds have competition for resources.
Some recommended native plants include High-bush cranberry, Nannyberry, Chockecherry, Grey dogwood, Pagoda dogwood, American hazelnut, American hornbeam, Black chokeberry and Juneberry.
For more in-depth information on how to properly remove buckthorn, including specific chemicals that are effective and their rate of application, visit the Minnesota DNR’s buckthorn management page.