Early spring is the best time to control musk thistles in pastures, and a number of available herbicides are effective, says Bruce Anderson, University of Nebraska Extension forage specialist.
“The rosette growth form is the ideal stage for controlling these plants this spring,” says Anderson. “That means spray herbicides soon, while your musk thistle plants still are in that rosette form, and very few plants will send up flowering stalks for hand digging later. After flowering, though, the shovel is about the only method remaining to control thistles this year.”
His current favorite herbicide is a relatively new one called Milestone, and Tordon 22K is also very effective, he says. Be careful if you use Tordon since it also can kill woody plants, including trees you might want to keep. Milestone and Tordon also will help control other weeds that usually appear later in the season.
“Other herbicides also can control musk thistles in pastures – like Forefront, Chaparral, Grazon, Cimarron, Overdrive and Curtail,” he says. “A tank mix of dicamba and 2,4-D also works very well. No matter which weed killer you use, though, be sure to read and follow label instructions, and be especially sure to spray on time.”