BACKGROUND: Scotch thistle is native to Europe and eastern Asia. It grows well in waste areas, pastures, rangeland, and along canal and stream banks.

OTHER COMMON NAMES:

DESCRIPTION: This biennial plant commonly grows 3 to 8 feet tall, but it may grow as high as 12 feet. Rosettes may be 4 feet wide. Large, spiny leaves are covered with dense hair, giving a grayish, blue-green coloration. Stems are winged. The flowers are violet to reddish with spine tipped bracts, blooming in mid-summer.

CONTROL: Biocontrol research is currently being conducted. Herbicides can offer good-to-excellent control when applied between rosette and pre-bud stages.