Managing Buckthorn on Your Land
What is it? Common buckthorn (Rhamnus cathartica) was first brought to Minnesota from Europe in the mid-1800s as a very popular hedging material. Shortly after its introduction here, it was found to be quite invasive in natural areas. The nursery industry stopped selling it in the 1930s, but many buckthorn hedges may still be found in older neighborhoods throughout Minnesota.
Why is it bad?
Buckthorn spreads quickly through Minnesota woodlands. It takes over the understory, choking out native flowers and shrubs that provide food and habitat for birds and wildlife. It also prevents saplings from taking root and growing, making it a long term threat for oaks, maples and other hardwood trees.
Why is buckthorn bad for water quality? Because it shades out groundcover plants, buckthorn causes runoff water pollution. Rain quickly washes exposed soil under the buckthorn into nearby water bodies, and continual erosion causes lakeshores and streambanks to slump and ravines to form in bluffs along the St. Croix and Mississippi Rivers.
Do you have buckthorn on your land? Signs to look for include unnaturally healthy shrubs that remain stubbornly green, long after the other trees and plants have gone dormant in the fall, an impenetrable fortress of spiny branches blocking access to woodlands, shoreline and trails, and a dearth of prairie and woodland flowers in the spring. Buckthorn has glossy green leaves with smooth gray bark, purple-black berries and spiny thorns. It is usually the first shrub to leaf out in the spring. Buckthorn is usually the last plant to lose its green in the fall and the first to leaf out in the spring.
How do you get rid of it? The Minnesota DNR has created an excellent resource -Buckthorn: What you should know, what you can do - that includes illustrations and tips for identifying buckthorn, strategies for buckthorn removal, and recommendations for native plants and shrubs that can replace buckthorn in your yard.
Be forewarned! There is no easy method for buckthorn control. The berries are spread widely by birds and small mammals and buckthorn can re-sprout or sucker from stumps and roots. Buckthorn management is labor intensive and effective control is difficult without some herbicide usage. Control strategies can include one or more of the following: cut stump treatments, basal bark treatments, foliar treatments, fire, crown removal and mechanical removal. If you live in the St. Croix Wild and River Scenic area, you can read the accepted management practices for buckthorn removal here.
Who can help me? The Washington Conservation District has weed wrenches that can be borrowed for up to one week at a time. There is no fee, but a $150 deposit is required. Call 651-330-8220 to learn more.
If you are removing buckthorn from a large area, you may want to consider using a herbicide. Learn more about Chemical Control for Buckthorn.
The WCD has also compiled a list of local buckthorn consultants that can help you manage buckthorn on your land.
Are there grants available? Not currently. You may be able to receive funding for buckthorn removal if it is part of a larger water-quality improvement project on your property.
Buckthorn Management Survey
If you have been battling buckthorn, we'd love to hear about your efforts. Please print and complete our survey and mail it to the WCD.
Learn more about Buckthorn: Minnesota DNR website