Polymerized and conventional (2,4-dichlorophenoxy)-acetic acid (2,4-D), (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T), 3,6-dichloro-o-anisic acid (dicamba), and 4-amino-3,5,6-trichloro-picolinic acid (picloram) were applied alone and in certain combinations to several brush species. Generally there were no significant differences in effectiveness between conventional and polymerized herbicides on honey mesquite (Prosopis juliflora (Swartz) DC. var. glandulosa (Torr.) Cockrell), huisache (Acacia farnesiana L. Willd.), Macartney rose (Rosa bracteata Wendl.), live oak (Quercus virginiana Mill.), whitebrush (Aloysia lycioides Cham.), and winged elm (Ulmus alata Michx.). Conventional granular picloram was more effective on yaupon (Ilex vomitoria Ait.) than polymerized formulations.