Roundup Concentrate Regional Wild Blackberry Vine and Brush Killer, 32-Oz (Only sold in OR, WA) Exclusive formula kills wild blackberry, knotweed, scotch broom and more Specially formulated to penetrate the waxy leaves of hard-to-kill weeds and brush Kills weeds to the root. Guaranteed! Consumer Guarantee: If for any reason you are not satisfied after using this product, simply send us original proof of purchase and we will replace the product or refund the purchase price. Rainproof in 30 minutes Visible results in 24 hours