I normally use SpeedZone to kill BLWs. A few customers and one new customers specifically has Johnson Grass. SpeedZone normally makes it wilt but does not kill. Will 2 appications spaced 10-14 days due the job? I'm looking for a general spray application before I purchase a 5' wick applicator for roundup. My "New" customer has 1 acre with lots of Johnson Grass.