Annual Bluegrass (Poa annua) Control in Non-overseeded Bermudagrass and Winter Overseeded Turfgrasses in Low Desert Arizona

Abstract

Annual bluegrass (Poa annua) is a cosmopolitan weed in most turfgrasses. In Arizona, the vast majority of the annual bluegrass is a true winter annual weed (Poa annua var. annua L. Timm.) that germinates in the fall, grows throughout the winter season, flowers profusely in the spring, and then dies as the summer temperatures rise. The weed seed remains in the soil all summer and then germinates during the next fall. The annual form var. annua is more upright in growth habit and prolifically produces stemmy seedheads that often grow in a circular pattern around the leaves, especially when the turf is mowed regularly.