I have a CareTree 501 (28" ball) , used to have a CareTree that would dig a 20" ball, and have worked with a Dutchman capable of digging a 36" ball. If your soil is at all challenging-read rocky or heavy clay- this Tree Toad will make a nice lawn ornament. When I was researching tree spades to buy, I checked it out, and recall that it was way too expensive for what it was. When it comes to seriously digging trees (as opposed to playing around), do not underestimate the value of weight. My Bobcat 742B with 1280 lbs of tree spade is about as light as I would care to use--found out the hard way. If you do not need to dig a ball bigger than 20", use a rugged nursery spade and dig it by hand. A friend had a Dyna Digger, and was very happy with it.