While extricating a division of U. nelumbifolia from a rather narrow necked glass vessel that I planted it in while it was much smaller, I accidentally ripped it into a bunch of pieces. One has some leaves and most of the stolon mass but there's also several 1.5'' or so pieces of stolon that broke off as well as some of the aerial "runners" attached to about a centimeter or two of stolon. Last time I tried to get stolon pieces to strike by putting them in wet LFS but they just rotted after a while. What should I do to get them started? (Perhaps live sphagnum?)