After cutting back the feeder roots from the bottom of the tree we see the area underneath is clogged with "potting soil" and there are very few feeder roots in this area. Several large roots emerge from this area and are pruned back, leaving some white stubs.
At this point it would be most expedient to use a hose and sprayer to clear away the potting soil. It could also be done by chopstick, but that would be time consuming and potentially more injurous to the remaining roots.
