What can I spray my pasture with to kill stickerweeds, or to be more precise, Spiny Amaranth? It started just being around where we feed hay in winter, but now is scattered over a whole lot of the pasture. Cattle eating the seed heads helps to spread it, too, I think. We spray early in the year with 2,4D for Buttercup and other weeds, but apparently the stickers aren't emerged that early.