Bermuda grass (Cynodon dactylon) is a warm-season perennial grass species found across tropical and subtropical regions worldwide. Introduced to the United States over 250 years ago, its ability to thrive in heat, tolerate drought, and rapidly recover from damage makes it a popular choice for turf. However, these aggressive growth characteristics also cause it to be widely considered a troublesome and difficult-to-control weed. This dual identity depends entirely on the context of its location. Understanding the plant’s unique biology is the first step toward effective management and removal.
The Dichotomy: Turf Grass or Invasive Weed
The classification of Bermuda grass depends on its purpose and geography, particularly relative to the “transition zone” where cool-season and warm-season grasses overlap. In the Deep South and Southwest United States, it is widely used as a primary turf grass for home lawns, athletic fields, and golf courses. Its exceptional durability and rapid growth rate allow it to handle heavy foot traffic and high temperatures better than most other species.
In contrast, Bermuda grass is despised when it invades cool-season lawns, such as those planted with tall fescue or Kentucky bluegrass, or when it creeps into garden beds. Since it is a warm-season variety, it turns brown and goes dormant in the winter, leaving unsightly patches in an otherwise green cool-season lawn. Homeowners can identify this grass by its fine-textured, low-growing, blue-green leaves and its signature finger-shaped seed heads. Wiry runners visibly spreading over sidewalks or into flower beds are a sure sign of its encroachment.
The Biology Behind Aggressive Spread
The difficulty in eradicating Bermuda grass stems from its vegetative reproductive structures. This species simultaneously produces two specialized types of spreading stems: stolons and rhizomes. Stolons are above-ground runners that creep horizontally along the soil surface, rooting at nodes to form new plants and rapidly colonizing adjacent areas. These structures allow for fast lateral expansion across a lawn or into a landscape bed.
Rhizomes are thick, scaly underground stems that allow the plant to survive mechanical and chemical disruption. These structures spread beneath the soil, sometimes as deep as six inches, and function as storage organs for carbohydrates and nutrients. The stored energy reserves enable the plant to recover quickly from drought, dormancy, and herbicide applications.
A single small fragment of a rhizome left behind in the soil can regenerate an entire new plant, which is why tilling or shallow digging often makes the problem significantly worse. The vigorous rhizome system can pass under concrete curbs and sidewalks, making physical barriers ineffective for long-term control. This combination of spreading mechanisms makes Bermuda grass an incredibly persistent competitor.
Control and Removal Strategies
Removing an established patch of Bermuda grass requires a multi-pronged approach that targets both the above-ground foliage and the energy-storing rhizomes beneath the soil. For non-chemical removal in planting beds, soil solarization uses the sun’s heat to kill the plant structures. To solarize, the area should be mowed low, watered thoroughly, and covered with a secured, clear plastic tarp. The tarp must remain in place for a minimum of four to six weeks during the hottest part of the year; some experts suggest twelve weeks or longer may be necessary to ensure deep rhizomes are killed.
Deep, careful mechanical removal is another non-chemical option, although it is labor-intensive and requires thoroughness. Every piece of root and rhizome must be carefully dug out, as any remaining fragment can quickly sprout a new plant. Installing a deep edging or barrier can help slow the spread into garden beds. In a cool-season lawn, cultural control involves maintaining the desired grass at a higher mowing height to shade and weaken the Bermuda grass, making it less competitive.
For larger scale removal, chemical control is often the most reliable method, typically involving a non-selective herbicide like glyphosate. Because of the rhizomes, a single application is rarely sufficient for eradication, and multiple treatments are often required, spaced approximately 30 to 60 days apart. The most effective time to apply these herbicides is when the grass is actively growing and healthy, allowing the chemical to be translocated down into the storage organs.
Selective herbicides offer an option for treating Bermuda grass scattered within an existing desirable lawn, though they are often more expensive and less potent than non-selective options. Products containing active ingredients like fluazifop can suppress the weed without harming certain cool-season grasses like fescue. Professionals often recommend a sequence of applications, sometimes combining glyphosate with fluazifop for enhanced control, though fluazifop requires a waiting period before reseeding due to its soil residual activity. Following removal, establishing a dense, competitive ground cover or turf is important to prevent re-establishment.