Centaurea cyanus is an annual weed mostly infesting winter cereals and rape. The aim of the study was to provide insights into the association between the seed germination characteristics and the herbicide sensitivity in C. cyanus in the presence of the genetic background control. Four populations of this species resistant to acetolactate synthase (ALS) inhibitors were tested. A germination study was conducted in a growth cabinet. Plants were sprayed at the 2- to 3-leaf stage with a field dose of florasulam (5 g/ha). There were four herbicide treatments dates, which included plants that germinated up to the seventh day, between eight and 12, 13 and 15, 16 and 20 days of the germination study. The germination dynamics of the four tested populations of C. cyanus resistant to florasulam was diversified. Three of them reached their maximum germination on the fourth day after sowing, however, the germination of the fourth population was spread over time with the highest number of germinated seeds found seven and twelve days after sowing. The germination time of the plants belonging to the resistant C. cyanus populations differentiated their reaction to florasulam. The conducted study indicated that the germination biology of ALS inhibitor-resistant populations of C. cyanus is diverse, which makes it difficult to introduce universal management strategies of this species into agricultural practice. Integration of control methods is recommended, including delaying the crop sowing date.