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 - guaranteed!* 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 gallon of water.