Thought I'd throw something out. I've dug up some pretty big fir, cottonwood, etc stumps with my Ford 1710 and 758 backhoe. Eventually the size gets to be a problem as I have to go farther and farther away from the stump to break the roots. I went to dig up a 6 inch diameter willow I think it was, couldn't break a root kept going farther away, finally cleaned the ground off so I could see it. It was 1" in diameter! I thought the hoe was screwed up. It wasn't. That 1" willow root was as tough as as steel cable, I finally hooked a chain up to it and pulled. It was 12 feet long, no kidding, that little 6" diameter tree had a 12' root that I probably could have used as a tow strap! Sometimes the little guys can fight!