The rosette grows and increases in diameter until the onset of cold weather. Then a fleshy tap root, which allows the plant to overwinter, develops. The following spring, new leaves originate from crown buds. The bolting stage begins when the seed stalk starts to form and continues until the first flower head appears. The plant begins flowering in early to mid-May and continues through August.
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.