Beenthere, The size tree it will take out varies with the type tree, soil conditions, and size of tractor. With my 3000 Ford, and in our NC red clay I can easily take out a 4" black pine, poplar, wild cherry, cedar, ect. Oak, Hickory, sweet gum is tougher, maybe 3". I cleared a 2 acre Plum thicket and lot's of them were over 4", course the roots run right on top of the ground.