I am finally trying to finish our pen. I am digging the trench around it today. There is granite, huge rocks, and I am getting blisters. Is there some type of edging tool or something I could use? How do you all do this? I tried paying my kids 5 bucks. They were thrilled and began excitedly for about 2 minutes, then said they didn't need the money and quit. I don't blame them. I have another 16 feet or so to go. Any suggestions? There must be a better way!