 and giant ragweed. Left undisturbed, they will become the most dangerous foes to corn plants. But in the early season, these weeds are at their weakest. Now is the time. A predator lurks. Sertain herbicide attacks, unleashing full residual power before weeds have a chance to emerge. Pre- or early post-application, they are hopeless against such effective chemistry. Sertain herbicide from BASF. Always read and follow label directions.