Seeds germinate throughout the growing season, but peak germination usually occurs mid-spring through early summer. Light is not required. A large portion of the seed bank remains dormant from year to year. Under field conditions, seed can survive for 20 years or more. A high percent of seed under dry storage can survive for at least 50 years.
Seed production is highly variable.
Dry, sunny conditions and calcareous soils favor seed production. Frequent cultivation, rain, or heavy, wet soils can inhibit seed set. One plant can produce up to 500 seeds. In the field, young plants seldom produce seed the first season. Root starch reserves are highest from mid-summer through early fall, but then decline rapidly with conversion to sugars.