This publication is designed to help the reader identify weeds and focus attention on many of the common and troublesome weeds found in lawns. This circular also provides cultural and chemical control recommendations. Refer to the table and sketches for a quick reference. Types of Weeds Weeds are usually classified by life cycle. Perennials come back every year for three or more years.
Annuals begin and complete their life cycles in one growing season.
In between are biennials, or plants that require two years to complete their lives, the first year usually as a rosette, then bolts and flowers the second year. Weeds are also classed as either grass or broadleaf plants. Both methods of classifying weeds are important in managing and controlling weeds. An annual like crabgrass requires different control and management practices than a broadleaf perennial like dandelion. Selective herbicides are used for effective control, along with some good management practices.