I got some certainty today for johnson grass. Its just 2 inches tall on one porperty I maintain. Last year I used msma and it kept coming back about 45 days after I hit it with msma. Anyone have luck with msma on johnson grass? Certainty sure is expensive. I know it is too early for msma temp. wise that is why I am gunna try certainty. Also round up was worthless on it. They must have been treating it for years with low doses of r/u and it is resistant to it.