My father in law enjoys doing all of his own Landscaping and since I do not do fert. he decided to go down to Lesco and bought that huge jug of prosecutor. He didnt ask the salesman about how much to mix and we started to look over that manual( or should I call it a book) about mixing. Anyways long story short, I know you guys in the fert. biz know from experiance what is the best mix for basic weeds in flower beds along with weeds in his rock boarders. How much prosecutor should he use to mix with a 3 gallon sprayer? Thanks for your help.