Grassy Weeds - St Augustine Lawn - Foxtails
BES-TEX WEED ID GUIDE · GRASSY WEEDS
Foxtails
Foxtail (Yellow & Green)
Common Name
Yellow Foxtail, Green Foxtail
Latin Name
Yellow Foxtail – Setaria pumila
Green Foxtail – Setaria viridis
Family
[PLACEHOLDER]
Life Cycle / Type
Annual · Grass
What Is It?
Yellow and green foxtail are bright green, clumping annual grasses common in turf and pasture areas. Both have a ligule that is a dense fringe of hairs and a bristly, spike-like seedhead. Yellow foxtail has a thicker seedhead with shorter bristles and long hairs on the upper leaf surface. Green foxtail has a smaller, greener, soft seedhead with long bristles and leaf blades that are not hairy.
Leaf Shape Identification (Quick ID)
Yellow Foxtail (Setaria pumila)
- Leaf tip: Sharp-pointed
- Long hairs on the upper leaf surface
- Ligule a dense fringe of hairs
- Flattened, sharply creased sheath
- Thick, coarse seedhead with short bristles
- Summer annual or perennial weed (NC State)
Green Foxtail (Setaria viridis)
- Leaf tip: Sharp-pointed
- Leaf blade flat, not hairy, slightly rough
- Ligule a dense fringe of hairs
- Collar hairy on the edges; sheath edges hairy
- Small, soft, green seedhead with long bristles
- Summer annual weed
One-Sentence Counter Script“If the seedhead is a bristly foxtail and the upper leaf is hairy, it is yellow foxtail. If the leaf is smooth, it is green foxtail.”
Soil Temperature & Germination
Foxtails are summer annual grasses that come up from seed.
[PLACEHOLDER]
Germination soil temperature for this species is not stated in the cited sources.
About 55°F
AgriLife guidance: soil temperature for spring pre-emergent timing against summer annual weeds (several days at this temperature).
Decision Question
Is the foxtail visible above the soil right now?
Why This Weed Comes Back
[PLACEHOLDER]
Thin turf that is not kept dense by proper mowing and fertilization
[PLACEHOLDER]
Learn the Basics
A healthy, thick lawn is the best defense against weeds.