How to Identify Foxtail
Foxtail grasses (Setaria species) are named for their distinctive seed heads: dense, fuzzy, cylindrical spikes that look like a small fox tail or bottlebrush. Three species are common in lawns: yellow foxtail (Setaria pumila), green foxtail (Setaria viridis), and giant foxtail (Setaria faberi).
Before the seed heads appear, foxtail grows in upright clumps with flat, slightly twisted blades. The easiest pre-seed-head identification is the ligule (the membrane where the blade meets the stem): foxtail has a fringe of hairs at this point rather than the clear membrane found in most lawn grasses.
Yellow foxtail has bristly seed heads with a yellowish tint and long hairs on the upper leaf surface near the base. Green foxtail has green to slightly purplish seed heads and smooth leaves. Giant foxtail grows 2 to 5 feet tall with large, nodding seed heads and hairy upper leaf surfaces.
Control Is All About Timing
Foxtail is a summer annual, so pre-emergent herbicide applied before germination is the most effective strategy. It germinates at the same soil temperature as crabgrass (55 degrees), so the same pre-emergent application timing covers both weeds.
Once established, foxtail is harder to control selectively. Quinclorac provides moderate post-emergent control of young foxtail plants. Fenoxaprop (Acclaim Extra) is more effective but is a professional-use product. Hand pulling is practical for small infestations because foxtail has a shallow root system and comes out easily when young.
