The seeds of some weed species may be dormant for many years, with only a small percentage germinating each year. Weeds generally mature earlier than the crop and often seeds will be dropped before crop harvest and remain in the field. Weeds are generally more competitive than crops and can often survive under unfavorable growing conditions. Early identification of emerged weed species is critical for choosing the best weed control methods. This guide will enable you to identify weeds at three growth stages.
Summer annuals complete their lifecycle from seed to maturity in less than one year.
They germinate in the spring, mature, set seed and die in the fall. Winter annuals germinate in the fall, overwinter as seedlings or small rosettes and mature, set seed and die the following spring or early summer. Some weeds are capable of both the summer and winter annual lifecycle. Biennials complete their lifecycles in less than two years. Germination and the production of an overwintering rosette of leaves occur the first year.