The plant is adapted to a range of habitats and soil types, but is especially well suited to relatively dry sites. The plant is a perennial, living an average of 3 to 5 years and frequently up to 9 years. The flower heads, enclosed by black-tipped bracts, are borne singly at the terminal ends of branches.
Seed is shed immediately upon maturation of the seed head.
The plant reproduces solely by seed. Seeds can survive in the soil for eight or more years. Seed germination occurs in the fall or early spring, depending upon moisture availability. Stem elongation occurs in June followed by flowering in July and seed dispersal in August. Spotted knapweed reduces livestock and wildlife forage, increases surface water runoff and soil sedimentation, and lowers plant diversity.