Weed control in a Bermuda grass lawn requires a proactive, year-round strategy due to the aggressive nature of both the turf and the weeds that invade it. Bermuda grass, a resilient, warm-season turf, has a dense growth habit that naturally crowds out many weeds when maintained under optimal conditions. An effective weed management plan must combine cultural practices that promote a thick lawn with the strategic use of selective herbicides. Ignoring this multi-step approach creates openings for invasive plants to take root and flourish.
Promoting Turf Health to Suppress Weeds
A dense, healthy stand of Bermuda grass is the most effective defense against weed invasion. To encourage this density, the grass should be mowed at a low height, typically between one and two inches. This promotes horizontal growth through its stolons and rhizomes. Cutting the grass too high encourages vertical growth, which thins the turf canopy and allows sunlight to reach the soil, a condition weeds exploit.
Watering practices should focus on deep, infrequent irrigation, supplying about one to 1.5 inches of water per week. This encourages the Bermuda grass to develop a deep, resilient root system, while shallow-rooted weeds struggle in the drier surface soil. Proper fertilization, focusing on nitrogen during the active growing season, feeds the turf and helps it outcompete emerging weeds.
This cultural approach is reinforced by applying pre-emergent herbicides, which establish a chemical barrier in the soil to prevent weed seeds from germinating. The initial application for summer annual weeds, such as crabgrass, should occur in early spring when soil temperatures consistently reach 55 degrees Fahrenheit. A second application eight to ten weeks later helps maintain the protective barrier throughout the growing season. A separate fall application targets cool-season weeds like henbit and chickweed.
Identifying Weed Types and Selecting Herbicides
Successfully eliminating existing weeds requires accurate identification to select the correct selective herbicide that will not harm the Bermuda grass. Weeds are broadly categorized into broadleaf weeds and grassy weeds, each requiring a different chemical mode of action. Broadleaf weeds, which include clover, dandelion, and spurge, have net-like veins and are easily distinguished from the turf.
For broadleaf control, herbicides containing active ingredients like 2,4-D, Dicamba, and MCPP (often sold as a three-way combination product) are highly effective and tolerated by Bermuda grass. Products like Triad Select are formulated to control a wide spectrum of these weeds without causing significant damage. Certainty herbicide is noted for its effectiveness against hard-to-control broadleaf weeds and sedges, such as nutsedge.
Grassy weeds, such as crabgrass and dallisgrass, are often more challenging because they are botanically similar to the turfgrass. Selective herbicides like Quinclorac are the industry standard for controlling crabgrass, and Bermuda grass tolerates this chemical well. Other options for grassy weed control include MSMA substitutes, though MSMA itself is now heavily restricted and often unavailable to homeowners. Always verify the chosen product is explicitly labeled for use on Bermuda grass to prevent non-selective damage.
Timing and Application of Post-Emergent Killers
The effectiveness of a post-emergent herbicide relies on applying it under optimal conditions when the weeds are most vulnerable. The best time to spray is when weeds are young and actively growing, ideally during the spring and early fall. This is before they have fully matured. Weeds are most susceptible when daytime temperatures are consistently between 65 and 85 degrees Fahrenheit.
Applying herbicides when temperatures exceed 90 degrees Fahrenheit can cause the chemical to become volatile or increase the risk of temporary injury to the Bermuda grass. Application should be performed on a calm day to prevent drift onto desirable plants in garden beds or neighboring lawns. Ensure no rain is forecast for at least 24 to 48 hours following application. This allows the weed sufficient time to absorb the chemical before it is washed off.
Herbicide concentrates must be accurately diluted according to the label’s instructions. Using the correct mixing ratio is the only way to achieve the intended weed kill without damaging the turf. Many post-emergent products benefit from adding a non-ionic surfactant, such as liquid dish soap, which helps the spray solution stick to the waxy leaf surface. Spot treatment, where only individual weeds are sprayed, is preferable to broadcast application. This minimizes the overall chemical load and reduces stress on the Bermuda grass. Personal protective equipment, including gloves and eye protection, should always be worn.
Non-Chemical Weed Control Methods
For those seeking to avoid chemical treatments, physical removal remains the most direct non-chemical method. Hand-pulling is most effective on young, isolated weeds and is a targeted approach that avoids turf injury. It is imperative to remove the entire root structure to prevent regrowth. This can be challenging with deep-rooted perennials like dandelion.
Manual techniques are supported by cultural practices that favor Bermuda grass, such as maintaining a dense, healthy lawn canopy. For small, contained areas, non-selective natural options can provide a solution. Horticultural vinegar, which contains a high concentration of acetic acid, can be sprayed directly on the weed to desiccate the plant’s tissue, but it is a non-selective killer that will damage or kill any plant it touches, including the Bermuda grass. Corn gluten meal can be used as a natural pre-emergent, but its effectiveness is often less reliable than synthetic herbicides. For severe non-turf areas, solarization involves covering the area with clear plastic sheeting during the hottest months to raise the soil temperature sufficiently to kill the weed roots.