Scientific Name: Cirsium horridulum
Also known as: Horrible Thistle
Yellow thistle is a winter annual or sometimes a biannual. The initial leaves form in a rosette. The mature leaves contain large toothed and cut lobes. The mature leaves are very spiny. Yellow thistle spreads by seeds attached to tuffs of soft white hairs which help in the spreading of the seeds. The flowers are produced in the late spring and seeds are produced over the summer. Yellow thistle is found along the east coast form Maine to Florida. It can be found along marshy areas west to Texas.
Yellow thistle is usually an annual, but can be a biannual. It grows along sandy marshy fields, shores and along the edge of wooded areas. The upright growth habit of yellow thistle aids in its control. Regular mowing will prevent the flower stalk from forming and seeds developing. Improving drainage should aid in the prevention of the establishment of the plants.
For optimum control, make your post-emergence herbicide application to yellow thistle that is young and actively growing.
Weed Photos: Courtesy of Dr. Lambert McCartey. Clemson University. Clemson, SC.