Please review video to observe the procedure demonstrated for treating rootbound nursery stock. The ash trees were extremely rootbound due to the vigorous growth habit of the species. Trees with roots left to circle after planting will develop significant problems, including: lack of stability, girdling roots, and reduced vigor. After this tree was lifted out of the ground, up to two inches of all sides of the rootball, including the bottom, were shaved off and large, circling roots were severed with sharp shears. As long as ample irrigation is supplied after, studies have shown that this procedure does not produce a decrease in overall tree vigor (http://hort.ufl.edu/woody/shave-prune.shtml).