Will Glyphosate Kill Bermuda Grass? The Definitive Answer
Yes, glyphosate can effectively kill Bermuda grass, but achieving complete eradication requires a strategic approach and understanding of the herbicide’s mechanism of action. While glyphosate targets a broad spectrum of plants, Bermuda grass’s resilience and aggressive growth habits necessitate careful application and potential repeat treatments for lasting control.
Understanding Glyphosate and Bermuda Grass
Glyphosate, the active ingredient in many widely available herbicides, works by inhibiting an enzyme crucial for plant growth: 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). This enzyme is essential for synthesizing certain amino acids required for protein production. When glyphosate is absorbed by a plant, it disrupts this process, ultimately leading to the plant’s death. However, Bermuda grass’s extensive rhizome system and ability to regrow from even small fragments make it a challenging target.
Bermuda grass is a warm-season perennial known for its rapid growth and tolerance to various environmental conditions. Its rhizomes, underground stems, allow it to spread aggressively and quickly recover from damage. This characteristic is what makes it so difficult to eliminate permanently. The herbicide must reach the rhizomes to effectively kill the entire plant.
Effective Glyphosate Application for Bermuda Grass Control
The effectiveness of glyphosate on Bermuda grass depends on several factors, including the concentration of the herbicide, the timing of application, and environmental conditions. Applying glyphosate when the Bermuda grass is actively growing and has a large surface area for absorption is crucial. This typically occurs during the warmer months.
The Importance of Application Timing
The ideal time to apply glyphosate is during the peak growing season when the Bermuda grass is actively photosynthesizing. This allows the herbicide to be readily absorbed and translocated throughout the plant, including the rhizomes. Avoid applying glyphosate during periods of drought or extreme heat, as this can reduce its effectiveness. Also, make sure not to apply it before or immediately after mowing. Allow the Bermuda grass to grow at least a few inches to provide ample surface area for herbicide absorption.
Application Techniques
- Spot Treatment: For smaller areas or isolated patches of Bermuda grass, a spot treatment using a handheld sprayer can be effective. Be careful to avoid spraying desirable plants.
- Broadcast Application: For larger areas, a broadcast sprayer can be used to apply glyphosate evenly across the entire area. This is a more aggressive approach but may be necessary for extensive infestations.
- Wick Application: In situations where desirable plants are interspersed with Bermuda grass, a wick applicator can be used to selectively apply glyphosate directly to the Bermuda grass blades.
Repeat Applications
Due to the resilience of Bermuda grass, a single application of glyphosate may not be sufficient for complete eradication. Repeat applications are often necessary to target regrowth from rhizomes. Monitor the treated area closely and reapply glyphosate as needed, typically every 2-4 weeks, until no new growth appears.
FAQs About Glyphosate and Bermuda Grass Control
1. What concentration of glyphosate is needed to kill Bermuda grass?
The concentration of glyphosate needed depends on the product being used and the specific Bermuda grass infestation. Always follow the manufacturer’s instructions carefully. Generally, a higher concentration is more effective, but it’s crucial to avoid exceeding the recommended dosage to prevent soil contamination and harm to other plants. A 2% solution, for instance, may be sufficient for spot treatments, while a 5% solution is better for extensive infestations.
2. How long does it take for glyphosate to kill Bermuda grass?
The time it takes for glyphosate to kill Bermuda grass varies depending on environmental conditions and the size of the infestation. Typically, you should start to see visible effects, such as yellowing and wilting, within 7-14 days. Complete kill may take several weeks, especially for mature Bermuda grass with extensive rhizomes. Multiple applications may be required.
3. Will glyphosate kill other plants in my lawn?
Yes, glyphosate is a non-selective herbicide, meaning it will kill virtually any plant it comes into contact with. This is why careful application is crucial, especially when treating Bermuda grass in a lawn with desirable grasses or ornamentals. Use a shield or cardboard to protect nearby plants during spraying.
4. Is glyphosate safe to use around pets and children?
While glyphosate is considered relatively safe compared to some other herbicides, it is still a chemical and should be handled with caution. Keep pets and children away from the treated area until the glyphosate has completely dried. Always wear appropriate protective gear, such as gloves and eye protection, when applying glyphosate.
5. Can I use a surfactant with glyphosate to improve its effectiveness?
Yes, adding a surfactant to glyphosate can significantly improve its effectiveness, especially on Bermuda grass. Surfactants help the herbicide spread and stick to the plant leaves, increasing absorption. Follow the surfactant manufacturer’s instructions for the correct dosage.
6. Does glyphosate kill Bermuda grass seeds?
Glyphosate primarily targets actively growing plants and is not effective at killing Bermuda grass seeds in the soil. This means that even if you successfully kill the existing Bermuda grass, new plants may emerge from seeds in the soil. Consider using a pre-emergent herbicide after glyphosate treatment to prevent new seedlings from establishing.
7. How do I prevent Bermuda grass from coming back after glyphosate treatment?
Preventing Bermuda grass from returning requires a multi-faceted approach. Consider combining glyphosate treatment with other methods, such as solarization (covering the area with clear plastic to heat the soil and kill seeds and rhizomes) or manual removal of rhizomes. Also, maintain a healthy lawn with proper fertilization and watering to help desirable grasses outcompete any remaining Bermuda grass. Pre-emergent herbicides are also valuable for preventing seedling establishment.
8. What are the alternatives to glyphosate for Bermuda grass control?
While glyphosate is a highly effective herbicide, some people may prefer alternative methods. These include:
- Manual Removal: Digging up Bermuda grass and its rhizomes can be effective for small infestations.
- Solarization: Covering the area with clear plastic for several weeks during the summer can kill Bermuda grass and its seeds.
- Vinegar-Based Herbicides: Horticultural vinegar (acetic acid) can kill Bermuda grass, but it is less effective than glyphosate and may require multiple applications.
- Non-selective Herbicides (Glufosinate): Glufosinate is another non-selective herbicide, that works similarly to glyphosate but by inhibiting a different enzyme.
9. Can I use glyphosate in my vegetable garden to control Bermuda grass?
Using glyphosate in a vegetable garden requires extreme caution. Glyphosate will kill any plant it comes into contact with, including vegetables. If you choose to use glyphosate, carefully protect your vegetable plants and avoid spraying on windy days. Allow sufficient time for the glyphosate to break down in the soil before planting new vegetables. Consider alternatives for weed control such as mulching or hand-pulling.
10. Is glyphosate harmful to the environment?
The environmental impact of glyphosate is a complex and controversial topic. While glyphosate is generally considered less toxic than some other herbicides, it can still have negative effects on the environment. It can contaminate water sources, harm beneficial insects, and disrupt soil ecosystems. Always use glyphosate responsibly and follow the manufacturer’s instructions carefully to minimize environmental impact.
11. Can I mix glyphosate with other herbicides to increase its effectiveness?
Mixing glyphosate with other herbicides can sometimes increase its effectiveness, but it’s important to consult with a qualified professional before doing so. Some herbicide combinations can be harmful to the environment or reduce the effectiveness of one or both herbicides. Always follow the product labels carefully.
12. What should I do if I accidentally spray glyphosate on a desirable plant?
If you accidentally spray glyphosate on a desirable plant, immediately rinse the plant with water. The sooner you rinse it off, the better the chance of minimizing damage. While the plant may still suffer some damage, rinsing can help remove the herbicide before it is fully absorbed. You can also try pruning any affected foliage.
By understanding the principles of glyphosate application and the unique challenges posed by Bermuda grass’s resilience, you can effectively control this persistent weed and achieve a healthy, desirable lawn. Remember to always prioritize safety and environmental responsibility when using herbicides.