• One particularly aggressive weed that can grow 1-2 inches a day is Palmer amaranth.???Palmer amaranth is our No. 1 weed to watch in Missouri and the Midwest right now,??? Bradley says.He says farmers facing extreme out-of-control weeds should try deep tillage, a practice that removes weeds but can also lead to soil erosion and other environmental concerns.Farmers moved away from heavy tillage of t