Centipede grass (Eremochloa ophiuroides) is a warm-season turf species valued for its low maintenance requirements in the southeastern United States. It is often called the “lazy man’s grass” due to its minimal need for fertilizer and infrequent mowing. However, when this grass invades a lawn composed of a different turf type, it becomes an aggressive and undesirable weed that is notoriously difficult to remove. Effectively eliminating centipede grass requires understanding its unique growth structure and applying targeted eradication strategies.
Identifying Centipede Grass and Its Growth Habits
Centipede grass is characterized by its distinct appearance and a growth pattern that makes eradication challenging. The turf has a medium-coarse texture and a bright, almost yellowish-green color, which often contrasts sharply with the deep green of other lawn grasses. This color difference is a primary visual cue for homeowners trying to spot the invasion.
Centipede grass is difficult to kill because of its robust method of spread: above-ground runners called stolons. These stolons creep along the soil surface, rooting at nodes to form a dense, interwoven mat. This efficient lateral expansion makes simple hand-pulling ineffective for established patches. The dense matting also creates a barrier, which reduces the penetration of water and chemical treatments into the soil.
Non-Chemical Elimination Methods
For homeowners who prefer to avoid synthetic chemicals, methods focusing on physical removal and environmental stress are available. Manually removing centipede grass is only practical for very small, isolated patches, where the entire stolon network and root system can be completely dug out. Because the grass spreads aggressively, it is imperative to remove every piece of the runner to prevent regrowth.
The most effective non-chemical approach for larger areas is soil solarization, which uses the sun’s heat to kill the vegetation. To solarize, the area must be mowed short, cleared of debris, and thoroughly watered to promote heat transfer. A clear plastic tarp, typically 2 to 6 mil thick, is then spread tightly over the soil and anchored at the edges for six to eight weeks during the hottest part of the year.
The clear plastic creates a greenhouse effect, raising the soil temperature high enough to be lethal to the plant material. Solarization also kills many weed seeds and soilborne pathogens. For very small spots, pouring boiling water or concentrated horticultural vinegar directly onto the patch can scorch and kill the foliage, but this is impractical for larger areas.
Targeted Herbicide Application Strategies
Chemical elimination is often the most reliable method for established or widespread centipede grass infestations. The choice of herbicide depends on whether the grass is mixed with desirable turf, requiring a selective approach, or if the entire area can be cleared using a non-selective treatment. For total area removal, a non-selective herbicide containing glyphosate is effective when applied to actively growing foliage. Multiple applications are still necessary to fully kill the tenacious stolons.
If the centipede grass is invading a desirable lawn, such as Bermuda or Zoysia, a selective herbicide must be used to preserve the surrounding turf. Centipede grass is particularly susceptible to certain chemicals, including those containing quinclorac, especially when temperatures are warm and the grass is actively growing. Another chemical option involves products containing sethoxydim, which can control grassy weeds without severely harming many broadleaf ornamental plants.
Timing and application technique are crucial for success, especially since the grass’s waxy leaves and dense mat can repel the spray. Herbicides must be applied when the grass is not under drought or heat stress, ideally when temperatures are below 90°F. Adding a non-ionic surfactant or an adjuvant helps the chemical penetrate the plant’s defenses and improves absorption. A common recommendation is to apply the herbicide two to three times, spaced 10 to 14 days apart, ensuring the runners are completely saturated.
Post-Eradication Lawn Restoration
Once the centipede grass is visibly dead, the area needs preparation before a new lawn can be established. The first step involves removing the dead thatch and runners, which can be accomplished through dethatching or light tilling to expose the soil. If a non-selective herbicide like glyphosate was used, a waiting period is necessary, typically seven to 14 days, to allow the chemical to break down completely before reseeding or sodding.
Soil testing at this stage is highly recommended, as centipede grass thrives in acidic soil, and the replacement turf may require a different environment. Based on the test results, soil amendments like lime can be incorporated to raise the pH if a less acid-tolerant grass is chosen. The area can then be replanted with seed, sod, or plugs of a new turf variety that is well-suited to the local climate and soil conditions.
Long-term prevention of re-establishment focuses on maintaining a healthy, dense replacement lawn that out-competes centipede grass. This includes proper mowing height for the new species, regular checks for nutrient deficiencies, and establishing edging to prevent runners from creeping in from adjacent areas. Centipede grass is sensitive to high nitrogen applications, so following a fertilization program tailored to the desired turf can help prevent its return.