By a large garden tractor, I am assuming you mean a Gravely rider?
If so, I have not. I've used one numerous times behind a walk behind. It works great until you hit a rock or a root. I've had a nice turned garden that looks ready to plant several times with a nice trench running off to the left more than once.:biglaugh:
I would imagine that it would work well behind a rider given more weight and control. I wouldn't mind trying, but finding a rider around here that won't require a second mortgage to get is next to impossible.