You didn't mix or apply correctly. 6 oz per gallon for spot spraying. For total vegetation control, CALIBRATE your sprayer. 7.4 oz per 1,000 square feet mixed in however many gallons of water YOUR sprayer puts out per 1,000 square feet. First step is cut back vegetation over 6 inches tall and REMOVE the debris. Wait 2 weeks for active new growth then spray. The preventative is the imazapyr which must make soil contact to work. It helps to read and follow the directions!
You didn't mix or apply correctly. 6 oz per gallon for spot spraying. For total vegetation control, CALIBRATE your sprayer. 7.4 oz per 1,000 square feet mixed in however many gallons of water YOUR sprayer puts out per 1,000 square feet. First step is cut back vegetation over 6 inches tall and REMOVE the debris. Wait 2 weeks for active new growth then spray. The preventative is the imazapyr which must make soil contact to work. It helps to read and follow the directions!