I've been using Snyder's Weed Control for ten years, and during that time I've never had an issue. There was once when a couple of months after the weed treatment, a few weeds came in a few areas. But they came right out and took care of it.

I recommended them to a friend who had all kinds of weeds in his yard. He also was really satisfied with their service. They stand by their word, and they'll come out and take care of you.