Bermuda grass (Cynodon dactylon) is a warm-season grass highly valued in some regions for its heat and drought tolerance, and its ability to create a tough, dense lawn. However, for many homeowners, especially those in cooler climates or attempting to grow cool-season grasses like fescue, Bermuda grass is a tenacious and unwelcome weed. Its aggressive growth habit, deep roots, and prolific seed production make it notoriously difficult to eradicate. If you’re battling a Bermuda grass invasion, prepare for a persistent effort, as it often requires multiple methods and applications to achieve control.

Why Bermuda Grass is So Difficult to Kill

Understanding what makes Bermuda grass so resilient is the first step in devising an effective eradication plan:

  • Aggressive Spreading: It spreads rapidly via three main mechanisms:
  • Deep Root System: Its extensive root system makes it highly drought-tolerant and difficult to remove manually.
  • High Resilience: It can regenerate from even small fragments of rhizomes or stolons left behind.
  • Herbicide Tolerance: Many common broadleaf weed killers have little to no effect on Bermuda grass.

Methods for Killing Bermuda Grass

Killing Bermuda grass effectively often involves a combination of strategies and a great deal of patience.

1. Chemical Control (Non-Selective Herbicides)

This is often the most effective method for complete removal of Bermuda grass, especially in large areas where you plan to reseed with a different type of grass.

  • Product Type: Use a non-selective herbicide containing glyphosate as the active ingredient. Glyphosate works by being absorbed through the plant’s foliage and translocated throughout the plant, including its root system (rhizomes and stolons), killing it from the inside out.
  • Application Steps:
    1. Mow Low: Mow the Bermuda grass as short as possible a few days before application.
    2. Water: Lightly water the area 24 hours before application. This encourages active growth, making the plant more receptive to the herbicide.
    3. Apply: Spray the herbicide evenly over the entire Bermuda grass area. Read and follow product instructions carefully regarding dilution rates, application methods, and safety.
    4. Wait: Allow 7-14 days for the herbicide to take full effect and the grass to yellow and die completely.
    5. Repeat: Bermuda grass is very tough. Expect to make 2-3 applications, waiting 2-3 weeks between each, to ensure all rhizomes and stolons are dead. New growth indicates another application is needed.
  • Safety Precautions: Always wear appropriate Personal Protective Equipment (PPE), including gloves, long sleeves, long pants, and eye protection. Avoid spraying on windy days to prevent drift onto desirable plants. Check the forecast for rain, as rain can wash away the product before it’s absorbed.
  • Considerations: Non-selective herbicides kill all vegetation they contact, so use with extreme caution near desired plants, trees, or shrubs.

2. Chemical Control (Selective Herbicides)

These are specific grass-killing herbicides that can control Bermuda grass without harming certain broadleaf plants or some desirable turf types (like fescue).

  • Product Type: Look for products specifically labeled for Bermuda grass control in cool-season lawns. Active ingredients like fluazifop-p-butyl or sethoxydim target grasses without significantly harming broadleaf plants. Some newer products containing mesotrione (like Tenacity) can also be used in specific cool-season turf types.
  • Application: These usually require multiple applications over several weeks, as they are less aggressive than glyphosate.
  • Considerations: Less effective for complete eradication compared to non-selective methods. Always confirm the herbicide is safe for your desirable turfgrass type before applying.

3. Solarization

This organic method uses the sun’s heat to “cook” the Bermuda grass and its seeds in the soil.

  • How it Works: Clear plastic sheeting traps solar radiation, raising soil temperatures to lethal levels for Bermuda grass and other weeds.
  • Steps:
    1. Mow Low: Cut the Bermuda grass as short as possible.
    2. Water: Water the area thoroughly to a depth of 6-12 inches. Moist soil conducts heat better.
    3. Cover: Lay clear (not black) plastic sheeting (4-6 mil thick) directly over the entire Bermuda grass area. Ensure it extends at least 1 foot beyond the infested area on all sides.
    4. Secure: Bury the edges of the plastic with soil, rocks, or other heavy objects to create an airtight seal, trapping the heat and moisture.
    5. Wait: Leave the plastic in place for 6-8 weeks during the hottest, sunniest part of the year. The hotter and sunnier it is, the more effective this method will be.
  • Pros: Organic, kills seeds, also controls other weeds and some soil pathogens.
  • Cons: Takes a long time, the area is unusable and unsightly during the process, and it may not be 100% effective in cooler climates or during cloudy periods.

4. Smothering/Deprivation (Sheet Mulching/Cardboard Method)

This organic method deprives Bermuda grass of sunlight, eventually killing it.

  • How it Works: Layers of organic material block sunlight, preventing photosynthesis, while also adding organic matter to the soil.
  • Steps:
    1. Mow Low: Cut the Bermuda grass as short as possible.
    2. Water: Lightly water the area.
    3. Lay Barriers: Lay down a thick layer (at least 2-3 layers, overlapping edges) of cardboard or newspaper directly over the grass. Remove any tape or labels from cardboard.
    4. Cover with Mulch: Cover the cardboard/newspaper with at least 6-12 inches of organic material such as wood chips, straw, compost, or a mixture.
    5. Wait: This method can take several months to a full growing season for complete eradication, as the grass slowly starves.
  • Pros: Organic, improves soil health, good for creating new garden beds.
  • Cons: Takes a long time, the area is unusable for planting until the grass is dead, and the appearance might be less desirable during the process.

5. Manual Removal (Digging)

Best suited for very small, isolated patches of Bermuda grass or for targeting individual runners.

  • How it Works: Physically removing all parts of the plant.
  • Steps:
    1. Dig Deep: Using a spade or garden fork, dig out the Bermuda grass, ensuring you go deep enough to get all the rhizomes (they can be several inches deep) and wide enough to get all stolons.
    2. Inspect: Carefully inspect the dug-up soil and the surrounding area for any remaining fragments of roots or runners. Even a small piece can regenerate.
    3. Dispose: Do NOT put Bermuda grass clippings or rhizomes in your compost pile unless you’re sure your compost gets hot enough to kill them. Bag them for disposal.
  • Pros: Chemical-free.
  • Cons: Extremely labor-intensive, very difficult to be 100% effective, high chance of regrowth from missed fragments.

Important Considerations Before You Start

  • Patience is Paramount: Killing Bermuda grass is rarely a quick fix. Choose a method (or combination) and be prepared for a multi-week or even multi-month battle.
  • Identify Your Grass: Double-check that what you’re fighting is indeed Bermuda grass. Misidentification can lead to ineffective treatments.
  • Prepare the Area: Regardless of the method, mowing low and clearing debris helps with effectiveness.
  • Follow Instructions: Always read and strictly adhere to the instructions on any herbicide product, including safety precautions, application rates, and re-entry intervals.
  • Post-Eradication Plan: Once the Bermuda grass is dead, be ready to replant quickly with your desired turfgrass or landscape plants to prevent new weed seeds from germinating or any missed Bermuda grass from re-establishing. Overseeding with a desired grass type immediately after eradication is crucial.
  • Ongoing Vigilance: Even after successful eradication, monitor the area regularly for new sprouts and address them immediately. Bermuda grass seeds can lay dormant for years.

By choosing the right method for your situation and committing to a diligent approach, you can successfully reclaim your lawn or garden from invasive Bermuda grass.