Barnyardgrass
Echinochloa crus-galli
A coarse summer-annual grass of thin, wet, or newly seeded turf, growing in spreading clumps with reddish stem bases.
Identification
Barnyardgrass is a tufted, erect summer annual grass that can grow several feet tall when unmowed, with relatively wide, smooth leaf blades marked by a prominent white midvein. A key diagnostic trait is the complete absence of a ligule and auricles where the blade meets the sheath, which separates it from most lawn grasses and from crabgrass; the leaves are rolled in the bud and the blades feel rough along the surfaces. The seedhead is a coarse, often purplish, nodding terminal panicle with numerous appressed or spreading branches bearing bristly spikelets. Its broad, midvein-marked blades, lack of a ligule, and stout reddish stem bases help distinguish it from crabgrass and other summer-annual grasses.
Symptoms & Damage
Where barnyardgrass establishes, it produces coarse, fast-growing clumps that overtop and shade the desired turf, creating a ragged, uneven texture and conspicuous seedheads that rise above the mowed surface. Its rapid growth lets it outcompete thin or young turf for light, water, and nutrients, thinning the desirable stand and leaving open, weedy patches that worsen as the plant seeds heavily before frost.
Biology
Barnyardgrass is a summer annual that completes its life cycle in one growing season and reproduces entirely by seed. Seedlings emerge from late winter or early spring through the summer as soils warm, favoring moist to wet conditions, and plants grow rapidly, flower, and set abundant seed before being killed by frost. The species tolerates a wide range of soils and can endure both wet soils and moderate drought, building a persistent seed bank that drives reinfestation the following spring.
Occurrence & Spread
Barnyardgrass favors moist to wet, sunny, disturbed sites and readily invades turf that is thin, newly seeded, or kept too short, particularly in low, poorly drained, or over-irrigated areas. It is well adapted to full sun but can survive partial shade, and it exploits openings in the canopy along edges, wet spots, and recently disturbed soil. Wet, fertile, open ground in summer is the classic situation for heavy infestations.
Favorable Conditions
Warm, moist, fertile, disturbed or newly seeded sites; thin turf.
Cultural Management
A dense, competitive stand maintained at the proper mowing height is the most effective cultural control, because barnyardgrass needs open soil and light to establish; promptly filling thin or worn areas denies it that opening. Improving drainage and avoiding overwatering remove the moist conditions it prefers, while sound fertility keeps the desired turf vigorous and shading the soil surface. On small or new infestations, plants can be hand-pulled before they seed, which is most practical when the soil is moist and before the heavy seedhead stage.
Further Reading
University extension resources — open in a new tab.
Related Reports
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Reports will appear here as they are peer-reviewed and published.