Yellow foxtail, Setaria glauca

Life Cycle



Reproducing only by seed.


Stem are normally round, but occasionally distinctly flattened.


Yellow foxtail is characterized by having a few, prominent, silky, kinky hairs (a) 3 - 10 mm long on the upper surface of the leaf blade just near the stem; ligule (b) a fringe of hair; no auricles; leaf sheaths split, their margins (c) smooth, green or slightly membranous and transparent.

Flowers and Fruit

Inflorescence a spike (C) 2 - 10 cm long, covered with numerous, yellow to orange bristles (d) with forward-pointing barbs. Spikelets (“seeds” or “grains”) slightly larger than Green foxtail, more prominently cross-ridged, and yellowish or straw-coloured. Flowers from July to August.

Roots and Underground Structures

Fibrous root system.


Yellow foxtail occurs throughout the agricultural regions of Ontario, having essentially the same distribution as Green foxtail but often being less abundant.


Corn yield loss (%)*: 1 % at 1 plant/m2 5 % at 5 plant/m2 Soybean yield loss (%)*: 1 % at 1 plant/m2 5 % at 5 plant/m2 *assumes that the weed has emerged with the crop and has been left uncontrolled all season.

Distinguishing Features

It is distinguished from the other foxtails and, indeed, from all other grasses in Ontario by the prominent silky, kinky hairs on the upper surfaces of the leaf blades just near the stem.


Yellow foxtail is not known to be toxic.

Human Health Issues

Yellow foxtail is not a known allergen.

Forage Quality

No information exists at this time.

Species Benefits

No information available at this time.

Often Mistaken For

Barnyard grass (ECHCG), Large crabgrass (DIGSA), Proso millet (PANMI), Witch grass (PANCA)

Power Ranking Corn

Power Ranking

↑ 1


Power Ranking Soybeans

Power Ranking

↑ 4


Biological Control

Currently none available for this weed. Currently none available for this weed. For the latest research on biological weed control:

Biopesticide Control

Currently none available for this weed.

Herbicide Resistance

Triazine resistant (WSSA group 5) populations exist in York Region (ON). For more information on weed resistance:

Figure #1.

Yellow foxtail: A. Plant. B. Leaf-base. C. Spike.

Figure #2.

Ligule: hairy.

Figure #3.

Leaf blade: Base of leaf blade covered with a number of straggly hairs that are roughly 1-2 cm in length.

Figure #4.

Leaf sheath: Hairless margins and very flat when compared to the round sheaths of green and giant foxtail.

Figure #5.

Seed head.