Weed Biology Weed Biology Effective weed management requires an understanding of weed biology.
Annual weeds emerge from seed, grow flower, produce seed, and die within a year.
Plants the next season must emerge from seed. Annual weeds are divided into winter and summer annual weeds, depending on growth pattern. They grow rapidly in the spring and are usually a problem only in the first cutting. Summer annual weeds are not a problem in the first cutting of established stands, but they appear in the second and later cuttings. Only a few weeds are classified as biennials, which require 14 to 24 months to complete their life cycle.