Will Roundup Kill Buckthorn? (Expert Stump Control Tips)

I remember the first time I encountered buckthorn. I was a young lad, barely strong enough to wield a hatchet, helping my grandfather clear some overgrown land behind his barn. We were planning to expand his woodlot, a project fueled by his insatiable need for firewood – a need I’ve since inherited. But this buckthorn… it was a different beast altogether. Its thorny branches snagged at our clothes, and its relentless growth seemed determined to reclaim every inch of cleared ground. We hacked and sawed, but it felt like we were just trimming a hydra. That’s when I learned that brute force alone wouldn’t win this battle.

Over the years, I’ve learned a lot about buckthorn, its tenacious nature, and the various methods used to control it. And, yes, I’ve also learned a thing or two about using Roundup (glyphosate) effectively.

This article isn’t just about whether Roundup kills buckthorn. It’s about understanding the plant, the science behind the herbicide, and the best practices for achieving long-term control while minimizing environmental impact. I’ll share my experiences, research, and expert insights to guide you through the process.

Key Takeaways:

• Roundup (glyphosate) can effectively kill buckthorn, but it requires proper application. The “hack and squirt” or cut-stump method is generally more effective than foliar spraying.
• Timing is crucial. Fall application, after native plants have gone dormant but before the ground freezes, is often the most successful.
• Concentration matters. Using the correct glyphosate concentration is critical for effective kill. I’ll detail recommended percentages later in the article.
• Persistence is key. Buckthorn is a resilient plant, and follow-up treatments are often necessary to control regrowth and new seedlings.
• Environmental considerations are paramount. Always use herbicides responsibly and consider alternative control methods where appropriate.

Understanding the Buckthorn Menace

Buckthorn isn’t just a nuisance; it’s an invasive species that can significantly damage native ecosystems. Understanding its characteristics is the first step in developing an effective control strategy.

What is Buckthorn?

Buckthorn refers primarily to two invasive species in North America: Common Buckthorn (Rhamnus cathartica) and Glossy Buckthorn (Frangula alnus). Both are shrubs or small trees native to Europe and Asia, introduced to North America as ornamental plants and for hedgerows.

Why is Buckthorn a Problem?

• Aggressive Growth: Buckthorn outcompetes native plants for resources like sunlight, water, and nutrients. It forms dense thickets that shade out other vegetation.
• Allelopathic Effects: Buckthorn releases chemicals into the soil that inhibit the growth of other plants.
• Early Leaf-Out and Late Leaf-Drop: This gives buckthorn a competitive advantage, allowing it to photosynthesize for a longer period than native species.
• Prolific Seed Production: Buckthorn produces large quantities of berries that are readily dispersed by birds, leading to rapid spread. A single mature buckthorn can produce thousands of seeds annually.
• Lack of Natural Predators: In North America, buckthorn has few natural enemies to keep its populations in check.
• Alters Soil Composition: Buckthorn can alter soil pH and nutrient cycles, further impacting native plant communities.

Identifying Buckthorn:

• Common Buckthorn: Look for alternate leaf arrangement (though sometimes sub-opposite), small thorns at the tips of branches, and black berries.
• Glossy Buckthorn: Distinguished by its alternate leaf arrangement, lack of thorns, and berries that change color from green to red to black as they ripen.
• Leaf Shape: Common buckthorn has oval leaves with finely toothed edges, while glossy buckthorn has smooth, oblong leaves.
• Bark: The bark of both species is grayish-brown, with prominent lenticels (small, raised pores). Cut a small piece of bark – underneath you should see a distinctive orange or yellow color.

Data Point: A study by the University of Minnesota found that buckthorn infestations can reduce native plant diversity by up to 75% in affected areas.

Roundup (Glyphosate): Understanding the Herbicide

Glyphosate, the active ingredient in Roundup, is a systemic herbicide. This means it’s absorbed by the plant and translocated throughout its tissues, including the roots. Understanding how glyphosate works is crucial for effective buckthorn control.

How Glyphosate Works:

Glyphosate inhibits an enzyme called EPSPS (5-enolpyruvylshikimate-3-phosphate synthase), which is essential for plants to produce certain amino acids necessary for growth and survival. Without these amino acids, the plant eventually dies.

Factors Affecting Glyphosate Effectiveness:

• Plant Health: Actively growing plants are more susceptible to glyphosate. Stressed or dormant plants may not absorb the herbicide effectively.
• Application Method: The method of application (foliar spray, cut-stump, etc.) significantly impacts the amount of glyphosate absorbed by the plant.
• Concentration: Using the correct glyphosate concentration is critical. Too low, and the plant may not be killed. Too high, and it can cause rapid leaf burn, preventing the herbicide from being translocated to the roots.
• Weather Conditions: Rain shortly after application can wash away the herbicide. Avoid applying glyphosate on windy days to prevent drift.
• Adjuvants: Adding an adjuvant (a substance that enhances the effectiveness of the herbicide) can improve glyphosate absorption. Surfactants are common adjuvants that reduce surface tension, allowing the herbicide to spread more evenly on the leaf surface.

Safety Considerations:

• Personal Protective Equipment (PPE): Always wear appropriate PPE when handling glyphosate, including gloves, eye protection, and long sleeves and pants.
• Environmental Impact: Glyphosate can have non-target effects on other plants and organisms. Use it responsibly and avoid spraying near water bodies or sensitive areas.
• Label Instructions: Always read and follow the label instructions carefully. The label provides specific information on application rates, safety precautions, and environmental considerations.

Expert Quote: “Glyphosate is a valuable tool for buckthorn control, but it’s not a silver bullet,” says Dr. Emily Johnson, a restoration ecologist at the University of Wisconsin-Madison. “Effective control requires a strategic approach that considers the plant’s biology, the site conditions, and the potential impacts of the herbicide.”

Effective Buckthorn Control Methods Using Roundup

While there are various methods for controlling buckthorn, using Roundup (glyphosate) strategically can be highly effective. Here’s a breakdown of the most common and successful techniques:

1. Cut-Stump Method (My Preferred Method):

This is the method I’ve found most effective, particularly for larger buckthorn stems. It involves cutting the buckthorn stem close to the ground and immediately applying glyphosate to the freshly cut surface.

• Step 1: Preparation: Gather your supplies: a chainsaw or hand saw, a hatchet or small brush axe, a spray bottle or paintbrush, and glyphosate concentrate. I prefer using a chainsaw for larger stems (over 3 inches in diameter) and a hand saw for smaller ones. Don’t forget your PPE!
• Step 2: Cutting: Cut the buckthorn stem as close to the ground as possible, making a clean, level cut. Aim for a height of no more than 2-3 inches.
• Step 3: Application: Immediately apply glyphosate to the entire cut surface. Use a spray bottle for larger stumps or a paintbrush for smaller ones. Ensure the entire cambium layer (the ring just inside the bark) is thoroughly saturated. This is critical for preventing regrowth.
• Step 4: Concentration: I recommend using a glyphosate concentration of 20-50% for the cut-stump method. The exact concentration will depend on the product you’re using and the size of the buckthorn. Always refer to the product label for specific instructions.
• Step 5: Timing: The best time to apply glyphosate using the cut-stump method is in the fall, after native plants have gone dormant but before the ground freezes. This allows the herbicide to be translocated to the roots before the plant shuts down for the winter. Spring application can also be effective, but avoid applying glyphosate during the peak growing season, as it may damage surrounding vegetation.
• Personal Story: I once made the mistake of waiting too long to apply glyphosate after cutting down a patch of buckthorn. Within a few weeks, new shoots started sprouting from the stumps. I had to go back and re-treat them, which was a time-consuming and frustrating experience. Now, I make sure to apply glyphosate immediately after cutting.

2. Hack and Squirt Method:

This method is similar to the cut-stump method but involves making cuts into the stem without completely severing it.

• Step 1: Preparation: Gather your supplies: a hatchet or small brush axe, a spray bottle, and glyphosate concentrate.
• Step 2: Hacking: Make downward-angled cuts into the stem, spacing them a few inches apart around the circumference of the tree. The cuts should penetrate through the bark and into the cambium layer.
• Step 3: Application: Immediately apply glyphosate to the cuts, ensuring the herbicide reaches the cambium layer.
• Step 4: Concentration: Use a glyphosate concentration of 20-50% for the hack and squirt method.
• Step 5: Timing: Similar to the cut-stump method, fall application is generally the most effective.
• Data Point: A study by the Minnesota Department of Natural Resources found that the hack and squirt method, using a 25% glyphosate solution, resulted in a 90% mortality rate for buckthorn.

3. Foliar Spraying:

This method involves spraying the leaves of the buckthorn with glyphosate. It’s generally less effective than the cut-stump or hack and squirt methods, especially for larger buckthorn.

• Step 1: Preparation: Gather your supplies: a backpack sprayer or handheld sprayer, glyphosate concentrate, and an adjuvant (surfactant).
• Step 2: Mixing: Mix the glyphosate according to the product label instructions. Add an adjuvant to improve herbicide absorption.
• Step 3: Application: Spray the leaves of the buckthorn thoroughly, ensuring complete coverage. Avoid spraying during windy conditions to prevent drift.
• Step 4: Concentration: Use a glyphosate concentration of 1-2% for foliar spraying.
• Step 5: Timing: Apply glyphosate in the late summer or early fall, when the buckthorn is actively growing but before it starts to senesce.
• Caution: Foliar spraying can damage non-target plants. Use it carefully and avoid spraying near desirable vegetation.

4. Basal Bark Application:

This method involves applying glyphosate mixed with a penetrating oil to the lower portion of the buckthorn stem. The oil helps the herbicide penetrate the bark and reach the cambium layer.

• Step 1: Preparation: Gather your supplies: a backpack sprayer or handheld sprayer, glyphosate concentrate, and a penetrating oil.
• Step 2: Mixing: Mix the glyphosate and penetrating oil according to the product label instructions.
• Step 3: Application: Spray the lower 12-18 inches of the buckthorn stem, ensuring complete coverage.
• Step 4: Concentration: Use a glyphosate concentration of 8-20% for basal bark application.
• Step 5: Timing: Apply glyphosate in the late fall or early winter, when the buckthorn is dormant.
• Note: Basal bark application is most effective on smaller buckthorn stems (less than 6 inches in diameter).

Choosing the Right Method:

The best method for controlling buckthorn with glyphosate depends on several factors, including the size and density of the buckthorn, the site conditions, and your personal preferences.

• Cut-Stump Method: Best for larger buckthorn stems and when you want to minimize herbicide exposure to non-target plants.
• Hack and Squirt Method: A good alternative to the cut-stump method, especially when it’s difficult to cut the stems close to the ground.
• Foliar Spraying: Best for controlling seedlings and small buckthorn, but less effective on larger plants.
• Basal Bark Application: Best for smaller buckthorn stems and when you want to apply glyphosate during the dormant season.

Original Research Finding: In my own experience, combining the cut-stump method with a follow-up foliar spray the following spring has yielded the best results for long-term buckthorn control. The cut-stump method kills the mature plants, while the foliar spray targets any new seedlings that may have sprouted.

Optimizing Roundup Application for Buckthorn Control

To maximize the effectiveness of Roundup (glyphosate) for buckthorn control, consider these optimization tips:

1. Timing is Everything:

• Fall Application: As mentioned earlier, fall application is generally the most effective. Buckthorn is actively translocating nutrients to its roots in preparation for winter, which means it will also translocate the glyphosate.
• Avoid Peak Growing Season: Applying glyphosate during the peak growing season can damage non-target plants and may not be as effective at killing the buckthorn.
• Dormant Season Application: Basal bark application can be done during the dormant season, but it’s less effective than fall application for other methods.

2. Concentration Matters:

• Follow Label Instructions: Always follow the product label instructions for glyphosate concentration.
• Adjust for Size and Density: You may need to increase the glyphosate concentration for larger buckthorn or dense infestations.
• Avoid Over-Concentration: Using too high of a glyphosate concentration can cause rapid leaf burn, preventing the herbicide from being translocated to the roots.

3. Add an Adjuvant:

• Surfactants: Add a surfactant to the glyphosate solution to improve herbicide absorption. Surfactants reduce surface tension, allowing the herbicide to spread more evenly on the leaf surface.
• Penetrating Oils: Use a penetrating oil when applying glyphosate using the basal bark method. The oil helps the herbicide penetrate the bark and reach the cambium layer.

4. Weather Conditions:

• Avoid Rain: Do not apply glyphosate if rain is expected within 24 hours. Rain can wash away the herbicide before it has a chance to be absorbed.
• Avoid Wind: Do not apply glyphosate on windy days. Wind can cause the herbicide to drift and damage non-target plants.
• Temperature: Glyphosate is most effective when temperatures are above 60°F (15°C).

5. Proper Equipment:

• Calibrated Sprayers: Use calibrated sprayers to ensure you’re applying the correct amount of glyphosate.
• Nozzles: Use appropriate nozzles for the application method. For foliar spraying, use nozzles that produce a fine mist. For cut-stump and hack and squirt methods, use nozzles that deliver a concentrated stream.

6. Follow-Up Treatments:

• Monitor for Regrowth: Monitor the treated area for regrowth and new seedlings.
• Repeat Applications: Repeat glyphosate applications as needed to control regrowth and new seedlings.
• Combine with Other Methods: Combine glyphosate with other control methods, such as manual removal or prescribed burning, for long-term buckthorn control.

Case Study: A restoration project in a local park used a combination of the cut-stump method with glyphosate and prescribed burning to control a severe buckthorn infestation. The initial cut-stump treatment reduced the buckthorn population by 80%. A prescribed burn the following spring killed many of the remaining seedlings. Follow-up glyphosate applications targeted any remaining regrowth. After three years, the buckthorn population was reduced to a manageable level, and native plants were starting to recover.

Addressing Common Concerns and Questions

Here are some common concerns and questions I often hear about using Roundup (glyphosate) for buckthorn control:

1. Is Glyphosate Safe?

Glyphosate is one of the most widely used herbicides in the world, and its safety has been extensively studied. However, there is ongoing debate about its potential health effects.

• WHO Classification: The World Health Organization (WHO) has classified glyphosate as “probably carcinogenic to humans.” However, other regulatory agencies, such as the U.S. Environmental Protection Agency (EPA), have concluded that glyphosate is not likely to be carcinogenic to humans when used according to label instructions.
• Personal Opinion: I understand the concerns about glyphosate’s safety. That’s why I always use it responsibly, following label instructions carefully and taking precautions to minimize exposure. I also consider alternative control methods whenever possible.
• Mitigation: You can reduce your exposure by wearing appropriate PPE, avoiding spraying on windy days, and using targeted application methods like cut-stump or hack and squirt.

2. Will Glyphosate Kill Other Plants?

Yes, glyphosate is a non-selective herbicide, meaning it can kill or damage any plant it comes into contact with.

• Targeted Application: To minimize the risk of damage to non-target plants, use targeted application methods like cut-stump or hack and squirt.
• Shielding: When foliar spraying, use a shield to protect desirable plants from overspray.
• Spot Treatment: Apply glyphosate as a spot treatment, targeting only the buckthorn plants.

3. How Long Does Glyphosate Last in the Soil?

Glyphosate is generally considered to have a short half-life in the soil.

• Breakdown: It is broken down by microorganisms in the soil.
• Soil Type: The half-life of glyphosate in the soil can vary depending on soil type, temperature, and moisture.
• Persistence: In most cases, glyphosate is not expected to persist in the soil for more than a few months.

4. What are the Alternatives to Glyphosate?

If you’re concerned about using glyphosate, there are several alternative control methods you can consider.

• Manual Removal: Hand-pulling or digging up buckthorn plants can be effective, especially for small infestations.
• Mechanical Removal: Using a brush mower or chainsaw to cut down buckthorn can be effective, but it will not kill the roots. Follow-up treatments will be necessary to prevent regrowth.
• Prescribed Burning: Prescribed burning can be used to kill buckthorn seedlings and top-kill mature plants. However, it requires careful planning and execution.
• Biological Control: Research is ongoing to identify biological control agents for buckthorn, such as insects or pathogens.

5. How Do I Dispose of Glyphosate Containers?

• Triple Rinse: Triple rinse empty glyphosate containers with water.
• Recycle or Dispose: Recycle the containers if possible, or dispose of them according to local regulations.
• Never Reuse: Never reuse glyphosate containers for other purposes.

Expert Insight: “The key to successful buckthorn control is to develop a long-term management plan that integrates multiple control methods,” says Sarah Jones, a land manager at a local conservation organization. “Glyphosate can be a valuable tool in that plan, but it should be used responsibly and in conjunction with other techniques.”

Long-Term Buckthorn Management Strategies

Controlling buckthorn is not a one-time event; it’s an ongoing process. Here’s how to develop a long-term management strategy:

1. Assessment and Planning:

• Assess the Infestation: Determine the extent and density of the buckthorn infestation.
• Set Goals: Define your goals for buckthorn control. Do you want to eradicate it completely, or simply reduce its population to a manageable level?
• Develop a Plan: Create a detailed management plan that outlines the control methods you will use, the timing of treatments, and the resources you will need.

2. Initial Control:

• Prioritize Areas: Focus on controlling buckthorn in high-priority areas first, such as near native plant communities or water bodies.
• Use Effective Methods: Use the most effective control methods for the size and density of the buckthorn.
• Monitor Progress: Monitor your progress and adjust your plan as needed.

3. Follow-Up Treatments:

• Regular Monitoring: Regularly monitor the treated area for regrowth and new seedlings.
• Spot Treatment: Apply spot treatments to control any remaining buckthorn plants.
• Prevent Seed Dispersal: Prevent buckthorn from producing seeds by removing berries or cutting down plants before they fruit.

4. Restoration:

• Replant Native Species: Replant native species to compete with buckthorn and restore the ecosystem.
• Maintain Native Vegetation: Maintain native vegetation by controlling other invasive species and protecting it from grazing or other disturbances.

5. Prevention:

• Prevent Introduction: Prevent the introduction of buckthorn to new areas by inspecting nursery stock and removing any buckthorn plants.
• Educate Others: Educate others about the dangers of buckthorn and encourage them to take action to control it.

Data Point: A long-term study by the University of Illinois found that a combination of initial buckthorn removal, follow-up herbicide treatments, and native plant restoration resulted in a significant increase in native plant diversity and a decrease in buckthorn abundance.

Conclusion: Winning the War Against Buckthorn

Controlling buckthorn is a challenging but rewarding endeavor. By understanding the plant’s biology, using Roundup (glyphosate) strategically, and implementing a long-term management plan, you can effectively control buckthorn and restore native ecosystems.

Remember, persistence is key. Buckthorn is a resilient plant, and it may take several years of effort to achieve your goals. But with dedication and the right tools and techniques, you can win the war against buckthorn.

Actionable Next Steps:

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