Lift a complete plant from its pot or from the ground but only when the plant is dormant and cut sections of the larger, more fleshy roots into 2- to 3-inch-long pieces. Cut the end of the root nearest the crown of the plant (that would be the top of the root) straight across, and cut the other end on a slant, so you can distinguish top from bottom and won't plant the cuttings upside down. Insert the root cuttings in pots or flats of rooting medium with the straight cut at the surface level of the medium. The cuttings will develop roots, and growing points or crowns will form at the top ends of the cuttings.