Nutsedge is a persistent weed often mistaken for grass, but it is a member of the sedge family. This perennial plant is difficult to eradicate because it reproduces primarily through small, underground tubers, called nutlets. These nutlets allow the plant to survive initial treatments and regrow repeatedly, making nutsedge a challenge for turf managers. The difficulty in a Bermuda grass lawn lies in finding a control solution that targets the sedge without causing damage to the desirable turf.
Identification and Non-Chemical Management
Identifying nutsedge is the first step toward control, as it looks different from true grasses like Bermuda grass. A distinguishing characteristic is its stem, which is triangular in cross-section, easily felt by rolling the stem between two fingers. Nutsedge leaves tend to be a lighter, glossy yellow-green color and grow significantly faster than the surrounding Bermuda grass, causing them to stand out just days after mowing.
The plant’s rapid, upright growth habit allows it to outcompete a closely mowed lawn. Its presence often indicates an issue with soil moisture, as nutsedge thrives in saturated, poorly drained soils. Changing irrigation habits to deep, infrequent watering stresses the sedge by drying out the topsoil where its young roots are most active.
Adjusting the mowing height of your Bermuda grass can help suppress nutsedge growth. Raising the cutting deck slightly encourages the Bermuda grass to grow denser and taller, shading the soil surface. This shading effect reduces the light available to nutsedge seedlings, hindering their establishment.
Physical removal is an option only for very small, isolated patches of young nutsedge. If hand-pulling, dig deeply to remove the entire plant, including any attached nutlets. Mature plants will simply break off above the nutlet, leaving the reproductive structure underground to sprout a new plant.
Targeted Herbicide Strategies
Chemical control of nutsedge in Bermuda grass relies on selective post-emergent herbicides designed to kill sedges without injuring the turf. Effective control is achieved using products containing specific active ingredients like halosulfuron-methyl or sulfentrazone.
Halosulfuron-methyl is a common and effective herbicide against both yellow and purple nutsedge. This active ingredient works by inhibiting an enzyme necessary for plant growth, causing the sedge to slowly die. Because the waxy cuticle on nutsedge leaves can repel liquid, these products often require the addition of a nonionic surfactant (NIS) to ensure the herbicide is fully absorbed.
Sulfentrazone is another selective herbicide that provides rapid injury symptoms, often visible within a few days of application. It works as a protoporphyrinogen oxidase (PPO) inhibitor, which disrupts the cell membranes of the nutsedge. Some formulations are available pre-mixed with an appropriate adjuvant, simplifying the application process.
Application timing is critical for successful control. Herbicides must be applied when the nutsedge is small, actively growing, and before it begins to produce new nutlets, typically in late spring or early summer. Targeting the plant at the three- to five-leaf stage ensures maximum herbicide is translocated to the underground tubers before they mature.
A single application is rarely sufficient to eliminate an infestation due to the staggered germination of nutlets. Sequential treatments, typically spaced three weeks apart, are necessary to control new shoots that emerge after the initial application. Always follow the product label precisely, paying close attention to temperature restrictions, as extreme heat can temporarily stress or damage the Bermuda grass.
Long-Term Prevention and Turf Health
Sustained nutsedge control shifts from immediate chemical eradication to improving the overall health of the Bermuda grass environment. Since nutsedge prefers wet conditions, focusing on soil management is a preventative measure.
Improving soil drainage through core aeration helps reduce compaction and allows water to move more efficiently through the soil profile. Aeration alleviates the saturated conditions that favor nutsedge and promotes a healthier root system for the Bermuda grass. Correcting drainage issues, such as pooling water or irrigation leaks, eliminates the moist microclimates where nutsedge thrives.
Proper fertilization is a major component of a healthy turf strategy. A balanced nitrogen fertilization program encourages the Bermuda grass to grow densely and aggressively. This competitive exclusion crowds out nutsedge seedlings by blocking sunlight from reaching the soil surface.
Vigilance is necessary for long-term success, as nutlets can remain dormant in the soil for several years. Regularly inspecting the lawn and treating any newly emerging nutsedge immediately prevents re-establishment. Catching the weed early, before it develops new underground tubers, stops the reproductive cycle.