I have a 4 strand electric fence and I am constantly fighting weeds growing up around it. I have sprayed roundup and it kills them but only for a month or so until new weeds take their place. I am looking for a more permanent solution. I am interested in a ground sterilizer type product that will kill them for a year or more. I saw this type of a product at home depot but it was really expensive and only sold in small bottles. I need to treat about 3 miles of fence as well as about 1 acre of driveway. Any suggestions?