Field experiments were conducted during 1968 to 1970 to determine the influence of time of herbicide application on control of kudzu [Pueraria lobata (Willd.) Ohwi]. Picloram (4-amino-3,5,6-trichloropicolinic acid) effectively controlled kudzu when applications were made as early as May 22 and as late as October 28. Acceptable control was obtained with rates of picloram 0.34 kg/ha or higher. In contrast, (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T) was most effective when applied during the first half of summer. Essentially no control of kudzu was obtained from 2,4,5-T applied 1 week before the first killing frost.