Life Cycle Annual or winter annual that reproduces by seed. Emergence Seedlings emerge mainly in the fall and early spring. Flowers Overwintered rosettes begin to flower near the end of May. Flixweed that emerges in spring starts to flower in mid-June. Both growth forms continue to flower through the summer. Reproduction Flixweed shatters easily and produces large quantities of seed.
Seeds can survive in the soil for more than three years.
Competition Overwintered rosettes are strong competitors because they grow rapidly in the spring and use valuable spring moisture before fields can be worked. Spring-emerging flixweed seedlings do not compete as well, especially in heavy crop stands. Flixweed can be a severe problem in perennial forage crops grown for seed. The winter annual adaptation is the strongest survival mechanism of flixweed. Crucial steps to control flixweed include prevention of seed production and control of fall rosettes.