Horseweed is an annual weed, winter or summer, depending on location. Horseweed is an upright growing plant and can reach 4 - 5 feet if not mowed. Horseweed grows in a basal rosette. The leaves which are oblanceolate in shape are 3- to 4-inches in length. The leaves alternate and have margins that are toothed. The stem of horseweed is simple and unbranched, and covered with hair. Horseweed has a taproot. The inflorescence is a panicle of heads with pink to white flowers. Horseweed spreads by seed produced in the summer. Horseweed is found through out the United States.
Horseweed is found mostly in thin turf and can occur following seeding. Horseweed will be found in landscape beds and along fence rows and other unmowed areas such as waste areas and fallow fields. Keep the weeds mowed and prevent the seedhead from developing. Follow a proper fertility program to promote competition from the turf.
Make your post-emergence herbicide application when horseweed is young and actively growing.