roundup, I've even started using it every were weed trimming is required side walks, porches etc. By the way you still need some kinda of trimmer because you have to cut the grass at least one time to remove winter grass and weeds from spring. round up is not as effective until it's hot out side. Be carefull with the spray width, my boss wasn't too happy with me the first year when I left a 18 inch wide dead zone around the entire house and all her flower beds. I have sense learned to narrow the pattern. Round up is good on the back too.
