August 3, 2022

Buckthorn creates problems for forests, wildlife and agriculture

The green leaves of buckthorn persist until November / December and will emerge in your woods. (Photo by Alex Roth, Friends of the Mississippi River)

Common Buckthorn (Rhamnus cathartica) and Common Buckthorn (Frangula alnus) are invasive, non-native plants native to Europe / Asia. Buckthorn can be found throughout Ohio, but it occurs most often in the northern, northeastern, and central-eastern areas of the state.

Introduced to the United States in the 1800s, buckthorn was sold as an ornamental and for use in hedges.

The description

Buckthorn plants produce black berries which are eaten by birds and scattered throughout the landscape. These berries are diuretic and lack the nutritional value found in berries from native plants. This can decrease the physical fitness of birds and other animals that eat the fruit.

buckthorn
Buckthorn plants produce black berries which are eaten by birds and scattered throughout the landscape. (Photo by Alex Roth, Friends of the Mississippi River)

Both species tolerate deep shade and full sun, making them extreme competitors with our native plants, often forming dense thickets and displacing native trees and shrubs. Large shrub or small tree, both species of buckthorn will grow 10 to 25 inches tall, taking on an oval shape as they mature.

Glossy Buckthorn prefers moist soils, while Glossy Buckthorn prefers to grow in dry to moist areas. Glossy buckthorn leaves have a very glossy leaf surface, alternating leaf arrangement, smooth margins, and eight to nine pairs of pronounced veins.

Glossy Buckthorn leaves have a dull green leaf surface, opposite / sub-opposite leaf arrangement, three to five pairs of veins that curve distinctly towards the tip, and finely toothed edges.

There are several lookalikes, including black cherry, Virginia cherry, and black chokeberry.

Your local district soil and water conservation office can provide technical assistance to help you identify and control buckthorn on your farm. Buckthorn is problematic not only from a forestry and wildlife perspective, but also from an agricultural perspective.

Common buckthorn is the alternate host for the crown rust fungus that affects oats, and it is also the overwintering host of soybean aphid eggs. In the upper Midwest, government incentives have been put in place to encourage the removal of buckthorn and help minimize the economic impact of crown rust and soybean aphid.

As late fall / winter approaches, this is a great time of year to take a walk around the edges of your fields and look for buckthorn. Its green leaves persist in November / December and will emerge in your woods.

Processing

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Applying herbicides to cut stumps can control buckthorn. (Photo by Bryan Weyant, Columbiana SWCD)

According to the Ohio State University Extension, a combination of mechanical / chemical control has proven to be one of the most effective methods for large plants or large stands of buckthorn. A cut-stump application of herbicide containing triclopyr, glyphosate, imazypyr or picloram at rates recommended for this method is effective.

Be aware that imazypyr and picloram remain active in the soil much longer than triclopyr and glyphosate and can therefore be taken up by the roots of desirable trees and shrubs nearby.

Smaller buckthorn plants can be controlled by hand pulling, using a weed wrench, or foliar spray. Be sure to read the herbicide label to see if buckthorn is listed as a species to be controlled and follow the mixing instructions for whatever method you choose.

As always, be sure to read and follow the directions on the entire herbicide label, as the label is the law. If you have any questions, want more information, or need a farm tour, contact your SWCD office.

Potential cost-shared funding from federal farm law programs may also be available to help you remove buckthorn. You can contact your NRCS or SWCD field office for more information on these programs.

A list of contractors specializing in removing invasive species may be available upon request from the SWCD office or your forester in the ODNR division of the forest service that covers your area.

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