A variety of thistles are found in turf. Like most, bull thistle is a biennial. It grows over the summer months. The leaves are alternate; blades are simple and form in a rosette. The leaves are unlobed to pinnately lobed. The blade tip is pointed and the margins are toothed with spines. The root is a fleshy taproot the first year and a fibrous root system forms the second year. The second year of growth, thistle stems elongate. The elongated stems have alternating leaves. Flowers are present from June through October on the elongated stems. The disk flowers are dark pink to purple with spined bracts. Bull thistle spreads by seeds. Thistles are found throughout the United States and Canada.
Weed Photos: Courtesy of Dr. Lambert McCarty. Clemson University. Clemson, SC.
Thistles that are actively growing and in the rosette to flower stage of growth can be controlled with a post-emergence herbicide application.
PowerZone® Broadleaf Herbicide
Q4® Plus Turf Herbicide for Grassy & Broadleaf Weeds
SpeedZone® Broadleaf Herbicide for Turf
SpeedZone® Southern Broadleaf Herbicide for Turf
SpeedZone® Southern EW Broadleaf Herbicide for Turf
Super Trimec® Broadleaf Herbicide
Surge® Broadleaf Herbicide for Turf
Trimec® 1000 Low Odor Broadleaf Herbicide
Trimec® 992 Broadleaf Herbicide
Trimec® Bentgrass Formula Broadleaf Herbicide
Trimec® Classic Broadleaf Herbicide
Trimec® Encore® Broadleaf Herbicide
Trimec® Southern Broadleaf Herbicide for Sensitive Southern Grasses
TZone SE Broadleaf Herbicide for Tough Weeds