Created with an exclusive formula, Roundup concentrate poison ivy plus tough brush killer combines two brush-killing ingredients to penetrate the waxy leaves and brush of hard-to-kill weeds to kill them down to the root. It also kills ivies and weeds like poison ivy, poison oak and poison sumac, as well as invasive vines and shrubs like kudzu and wild blackberry. Simply mix 6 fl-oz of the concentrate with 1 gal of water.