Goosegrass (Eleusine indica) is a tenacious annual grassy weed that challenges turf managers and homeowners maintaining Bermuda grass lawns. It is difficult to control because it tolerates compacted soils and low mowing heights, conditions Bermuda grass often experiences. The control strategy must rely on selective treatments that target the weed without harming the desirable Bermuda grass. A successful approach combines proactive cultural practices, precise pre-emergent herbicide timing, and selective post-emergent applications.
Key Characteristics and Growth Cycle
Goosegrass is easily identified by its distinctive physical appearance, often growing in a dense, prostrate, mat-like rosette. A key visual feature is the white or silver-colored center, or collar, at the base of the plant where the leaf sheaths meet the stem. The leaves are typically folded and flat, giving the plant a more robust look than its relative, crabgrass.
This weed is a summer annual, but it is one of the last summer grasses to germinate. Germination begins when soil temperatures consistently reach 60 to 65 degrees Fahrenheit at a four-inch depth. This emergence timing is several weeks later than other common grassy weeds, requiring a separate control strategy. The plant develops characteristic flat, zipper-like seed heads that radiate outwards, producing thousands of seeds that ensure its return in subsequent years.
Non-Chemical Removal and Prevention Methods
While chemical control is necessary for large infestations, cultural practices reduce overall weed pressure. Hand-pulling is a viable option for small, scattered patches of goosegrass, but it must be done when the plants are young, before they have produced seeds. Removing mature plants with seed heads risks further spreading the problem.
Goosegrass thrives in areas of poor soil health, particularly where the soil is heavily compacted. Core aeration improves soil structure, allowing for better water infiltration and Bermuda grass root growth, making the area less hospitable to the weed. Bermuda grass is typically mowed low, but maintaining the highest recommended height for your cultivar helps the turf canopy shade the soil, discouraging goosegrass seed germination.
Strategic Use of Pre-Emergent Herbicides
Pre-emergent herbicides are the most effective tool in goosegrass management because they prevent the weed from establishing. These products form a chemical barrier at the soil surface that disrupts the germination process of the seed. Timing the application is critical, as the product must be in place before the soil reaches the 60 to 65 degree Fahrenheit temperature threshold.
A single application often will not provide season-long control due to the extended germination period of goosegrass. For reliable prevention, it is recommended to use a split application approach, applying half the maximum seasonal rate in the early spring and the second half six to eight weeks later. Common active ingredients safe for use on established Bermuda grass include prodiamine, pendimethalin, and dithiopyr.
The pre-emergent product must be watered into the soil immediately after application, typically with about a half-inch of irrigation or rainfall, to activate the chemical barrier. Without this activation, the herbicide remains on the soil surface and can be easily broken down by sunlight or disturbed by foot traffic, rendering the treatment ineffective. Following label instructions regarding application rates is necessary to ensure efficacy against the weed while protecting the Bermuda grass.
Selective Post-Emergent Treatment Options
Existing, established goosegrass plants require post-emergent herbicides, which are generally less effective than pre-emergents, especially on mature clumps. Once the plant has developed a fibrous root system and multiple tillers, it becomes highly tolerant of most selective chemicals. Post-emergent treatments are most successful when applied to goosegrass seedlings that have fewer than four leaves.
Active ingredients like quinclorac, while effective on other grassy weeds such as crabgrass, have limited efficacy on goosegrass and should not be relied upon for control. Selective control in Bermuda grass is often achieved with products containing active ingredients such as fenoxaprop-P-ethyl or specific formulations of MSMA, where its use is permitted by local regulations. MSMA, an organic arsenical herbicide, has historically been highly effective but is restricted in many areas.
Multiple applications, spaced according to the product label, are necessary to achieve acceptable control of goosegrass. Large, established plants may require a repeat application every seven to ten days until the weed is completely eliminated. Applying these herbicides when air temperatures are moderate and the Bermuda grass is not under heat or drought stress minimizes the risk of temporary turf discoloration or injury.
Maintaining a Dense Bermuda Turf
The long-term strategy for goosegrass control centers on cultivating a dense, healthy Bermuda grass stand that naturally crowds out weeds. A thick turf canopy prevents sunlight from reaching the soil, which is necessary for goosegrass seeds to germinate. This preventative measure significantly reduces the need for chemical intervention in future seasons.
Bermuda grass is a heavy feeder that requires regular fertilization during its active growing season to maintain density. Applying between one and one-and-a-half pounds of nitrogen per thousand square feet monthly during the summer promotes vigorous growth. Proper irrigation, characterized by deep, infrequent watering, encourages deep root growth, making the turf more resilient to stress and better able to compete against opportunistic weeds like goosegrass.