Goosegrass (Eleusine indica) is a stubborn annual grassy weed that thrives in areas where desirable turf is stressed, particularly in high-traffic zones and compacted soil. As a summer annual, it grows throughout the warm season before dying with the first heavy frost, but it leaves behind a large volume of seeds for the following year. Eliminating goosegrass requires a strategic, multi-faceted approach combining cultural practices and chemical treatments due to its adaptability and tendency to develop herbicide resistance.
Identifying Goosegrass and Its Growth Cycle
Goosegrass plants grow in a flat, dense rosette or clump that lies close to the soil surface. A key identification feature is the whitish-silver color at the base of the plant, known as the collar, often called “silver crabgrass.” The stems, or tillers, radiate outward from a central point, and they are noticeably flattened, unlike the round stems of most turfgrasses.
As the plant matures, it produces characteristic seed heads resembling a zipper, with two to seven spikes radiating from a central point. This annual weed begins to germinate later than many other summer weeds, typically in mid-to-late spring or early summer, when soil temperatures consistently reach between 60°F and 65°F at a four-inch depth. Its growth peaks during the heat of summer, and each plant can generate thousands of seeds from July through September, which will remain viable in the soil for future seasons. Understanding this life cycle is important for timing control efforts effectively.
Manual and Cultural Control Methods
Non-chemical management focuses on making the lawn an inhospitable environment for goosegrass, thereby reducing the need for herbicides. One of the most direct methods for small infestations is manual removal, which must be performed before the plant produces its zipper-like seed heads. When hand-pulling, remove the entire central crown, as this is the growing point; unlike many other grasses, goosegrass cannot regrow once this central crown is severed.
The preferred habitat of goosegrass is compacted, thin turf, so improving soil health and turf density is an effective preventative measure. Goosegrass thrives in high-traffic areas where desired turf struggles to establish a strong root system. Implementing core aeration periodically helps to relieve compaction, improving soil drainage and allowing turfgrass roots to penetrate deeper, increasing the overall competitiveness of the lawn.
Adjusting mowing and watering practices further discourages goosegrass establishment. Maintaining a taller mowing height—the highest setting tolerated by your specific turf type—creates a dense canopy that shades the soil surface. This shading prevents the light necessary for goosegrass seeds to germinate, and a healthy, dense lawn naturally outcompetes the weed. The practice of deep, infrequent watering encourages the turfgrass to develop deep roots, while the drier soil surface discourages the shallow-rooted goosegrass from establishing itself.
Choosing the Right Herbicides
Chemical control is often necessary for large or persistent goosegrass infestations, relying on two strategies based on the weed’s growth stage. The most effective long-term strategy relies on using pre-emergent herbicides, which create a chemical barrier in the soil that prevents the goosegrass seeds from germinating. These must be applied in the spring before the soil temperatures reach the 60°F to 65°F threshold required for germination.
Common active ingredients in pre-emergent products effective against goosegrass include prodiamine, dithiopyr, and pendimethalin. Because goosegrass germinates later than many other summer weeds, a single application may not provide season-long control. A second, sequential application approximately six to eight weeks later may be necessary to maintain the protective barrier and reduce the seed bank in the soil.
If the timing for pre-emergent application is missed, or if the weed has already emerged, post-emergent herbicides are required to kill the visible plants. Post-emergent treatments are most effective when applied to young goosegrass seedlings, ideally before they develop more than two to four tillers. Controlling mature, multi-tillered goosegrass often requires higher application rates or multiple treatments spaced several weeks apart. Active ingredients commonly used for post-emergent control include quinclorac, fenoxaprop-p-ethyl, and topramezone. It is crucial to use a product specifically labeled for grassy weeds, as those intended only for broadleaf weeds will not control goosegrass, and to always follow label instructions to ensure compatibility with your specific turfgrass species.