Flower color varies from purple to a deep reddish-pink. The flowers of musk thistle are large, solitary and beautiful. Each flower head is located at the tip of a long stem or branch, which bends or nods and twists as the flower increases in size and matures. The plant dies after all its seeds mature. Musk thistle is not a serious weed problem in crops requiring a spring seedbed preparation.
Tillage easily eradicates rosettes established during the preceding summer or fall.
Musk thistle, however, can be a problem in fall-planted grains, alfalfa or clover if conditions are favorable for seedling establishment and winter survival. Check fence rows, ditch banks and waste areas periodically for musk thistles. Newly established thistle rosettes are inconspicuous and you may not see them until they bloom the following year. The economic impact of musk thistle is greatest in pastures and rangeland. Moderate infestations of musk thistle reduce pasture yields an average of 23 percent.