Using Herbicide to Kill Buckthorn: Tips from a Pro

Buckthorn is a notorious invasive plant that wreaks havoc on both natural ecosystems and landscaped areas. Originally introduced for ornamental purposes, this aggressive species spreads rapidly, displacing native plants and reducing biodiversity. Its thick, impenetrable thickets create a hostile environment for wildlife, and its ability to outcompete native vegetation poses a serious challenge for land managers, gardeners, and homeowners alike. While mechanical removal methods like pulling or cutting can help, they often fall short without chemical intervention. Herbicide use is one of the most reliable ways to manage large or stubborn infestations. In this guide, we’ll cover professional tips for using herbicide to kill buckthorn effectively, offering insights into best practices for timing, application, and follow-up care to ensure lasting results. If you’d like to explore more about buckthorn and how to remove it, read our blogs Identifying Buckthorn in your Woodlands: 5 Obvious Signs and 7 Ways to Effectively Remove Buckthorn.

Understanding Buckthorn and Its Challenges

Buckthorn’s tenacity is partly due to its ability to grow in a wide range of conditions, from sun-drenched areas to shaded understories. It has a deep root system that enables it to resprout after cutting, making it difficult to control through mechanical means alone. Additionally, buckthorn’s berries are prolific seeders, allowing it to spread far and wide through the droppings of birds and other animals. These characteristics make buckthorn especially tough to eradicate without a targeted approach that includes herbicide treatment.

Herbicide Selection: Choosing the Right Product

For effective buckthorn control, choosing the right herbicide is critical. The two most commonly recommended active ingredients are glyphosate and triclopyr:

Glyphosate: This non-selective herbicide is ideal for killing buckthorn, but it also poses a risk to other plants because it targets all vegetation. Glyphosate works by inhibiting the plant’s ability to produce essential proteins, leading to its death. Professionals recommend using glyphosate in areas where native plants have already been displaced or when precision application is possible to avoid collateral damage.
Triclopyr: Unlike glyphosate, triclopyr is selective, primarily affecting woody plants like buckthorn without harming grasses and other non-target species. This makes it a great choice for sites where preserving the surrounding vegetation is important. Triclopyr disrupts the plant’s growth processes, leading to its gradual death. It’s often the preferred herbicide in sensitive environments, such as near wetlands or prairie grasslands, where other species must be protected.

Pre-Treatment Preparation

Before applying herbicide, proper preparation of the site is essential. Begin by assessing the size and density of the buckthorn infestation. For dense thickets, consider cutting larger trees and shrubs down to stumps, which reduces the biomass you’ll need to treat with herbicide and improves the likelihood of success. When possible, clear the surrounding area of debris, fallen branches, or leaves to ensure that the herbicide is applied directly to the buckthorn and not wasted on unnecessary plant material.

Timing Matters: Why Fall is the Best Season for Treatment

One of the most important factors in successful buckthorn eradication is timing. While herbicide can be applied during most of the growing season, late summer and early fall are considered the best times for treatment. During this period, buckthorn is preparing for dormancy and is actively drawing nutrients into its roots. Applying herbicide during this phase ensures that the chemicals are absorbed deep into the plant’s root system, increasing the likelihood of killing it completely. By contrast, applying herbicide too early in the season may only damage the leaves, allowing the plant to recover and resprout.

Cut-Stump vs. Foliar Applications

Two of the most commonly recommended application methods are cut-stump and foliar spraying:

Cut-Stump Treatment: This method involves cutting the buckthorn plant down to a stump and applying herbicide directly to the fresh cut. It is especially effective for large trees or shrubs and works by allowing the herbicide to be absorbed directly into the plant’s vascular system. For the best results, apply the herbicide immediately after cutting the stump—delaying even by a few minutes can reduce the plant’s absorption. If you’d like to explore more about removing buckthorn, read our blog Special Tools for Removing Buckthorn: 5 Failproof Choices
Foliar Application: For smaller plants or dense infestations, foliar spraying—where herbicide is applied directly to the leaves—can be effective. However, this method carries a higher risk of damaging nearby plants if the herbicide drifts. When using foliar sprays, be mindful of weather conditions, particularly wind, which can carry the herbicide onto non-target vegetation.

Safety Considerations When Handling Herbicides

Safety should always be a priority when working with herbicides. These chemicals can be harmful if misused, so it’s essential to follow the manufacturer’s guidelines and wear the appropriate protective gear. This includes gloves, goggles, long sleeves, and pants to avoid skin contact. Make sure to work in well-ventilated areas, and avoid applying herbicide on windy days to reduce the risk of drift onto non-target species. Additionally, take care to protect nearby water sources, as runoff from herbicide-treated areas can contaminate ponds, lakes, or streams.

Post-Treatment Follow-Up: Monitoring and Reapplication

Buckthorn is a resilient plant, often requiring multiple treatments to fully eradicate it. After the initial application, it’s essential to monitor the site regularly for signs of regrowth. New shoots may emerge from stumps or the seed bank, particularly if the initial herbicide application wasn’t thorough. Follow-up treatments may be needed in subsequent years to target any resprouting buckthorn. Regular monitoring will ensure that any new growth is addressed quickly, preventing buckthorn from reestablishing itself.

Restoring Native Vegetation

Once the buckthorn has been eradicated, it’s important to consider the restoration of the area with native vegetation. Removing buckthorn opens up space for native plants to thrive, which can help prevent future infestations. Planting native species not only improves biodiversity but also strengthens the ecosystem, making it more resistant to future invasions. Grasses, wildflowers, and native shrubs are excellent choices for restoring balance to previously infested areas.

Conclusion

Eradicating buckthorn with herbicides is a method that, when done correctly, can yield lasting results. By understanding the challenges posed by this invasive species and selecting the right herbicide and application method, you can effectively control buckthorn infestations. Remember that persistence is key—buckthorn may require several treatments and careful follow-up monitoring. By integrating herbicide use with good safety practices and a commitment to native plant restoration, you’ll be well on your way to creating a healthier, more balanced landscape free from the invasive grip of buckthorn. For more detailed information and tailored advice, visit our page on buckthorn removal. For support on your next buckthorn removal project, please feel free to reach out through our contact form, and our team will be happy to help.

Table of Contents