Several weed species grouped in this classification have narrow leaves and somewhat resemble grasses. Their control, however, is similar to other broadleaf weeds. Weeds are also categorized by their life cycle and growth habit. Annual weeds can be classified by the season when their seed normally germinates . Winter annuals germinate during late summer or fall , persist as an immature plant throughout the winter months, and produce more vegetative growth, flowers and seed in the spring.
Summer annuals germinate in the spring and produce seed in summer or fall.
Annual weeds complete their life cycle in 1 year. Biennials complete their life cycle in 2 years, developing to partial maturity during the first growing season, with flowering and eventual death during the second season. Perennial plants can persist over long periods of time, usually over-wintering in a dormant state. These species resume growth the following season from stored energy. They may also reproduce from seed.