Weed management begins with a survey of the site. Weeds should be identified and the level of weed pressure noted. Weeds can be classified according to their life cycles. Summer annuals emerge in the spring, flower, and set seed before the first frost. In cultivated fields, summer annuals tend to predominate as the primary weed type.
Winter annuals germinate at the end of the summer and overwinter as small, dormant, green plants.
Biennials need at least two seasons to complete their life cycle and, like annuals, biennials die after flowering. Perennials which survive more than two seasons can propagate by seed or vegetative reproduction. Knowing the weed life cycle is important in determining the optimal timing of a herbicide application or cultural practice. It is also important to scout the weed population during and after the growing season in order to assess the success of the weed control program. Herbicides are available that may be safely used to control weeds in cut flowers.