Yellow Foxtail is an annual grassy weed that is also known as Summer-grass, Golden Foxtail or by its scientific name, Setaria glauca. This lawn weed is named for its long, golden seed heads that resemble a fox's tail.
Yellow Foxtail can be identified as a coarse, tufted, annual grassy weed. It has a continuous, narrow collar and compressed sheaths that are tinged with red near the base and include a prominent mid-vein. The flat blades of this lawn weed often spiral upward and are hairy on the upper surface (near the ligule).
This grass-like weed is best identified by its seed head, which is a bristly panicle reaching up to 6 inches in length. These bristles turn yellow to gold at maturity, hence the names Golden or Yellow Foxtail.
Preferring fertile soils, this lawn weed is often found growing in croplands, nurseries and turf grass—especially in lawn areas. Yellow Foxtail thrives throughout much of North America.
These grassy weeds are also annuals, meaning they live for only one season and are typically easy to control because they lack the complex underground structures needed to spread new plant growth through creeping roots. Still, annuals produce tons of seeds that can infest and dominate your yard under the right conditions.
Because of its preference for nutrient-rich, high-fertility soils, Yellow Foxtail is a frequent invader of lawns and landscaping. Although some cultural lawn weed control methods—including lower lawn-mowing heights—can occasionally discourage spreading, professional control treatments are the only way to ensure weed removal without damaging desired grass types in your lawn.