Moss

sometimes it just grows
otherwise, here's a link from slippertalk.com where lance birk describes growing it....
(um, it's okay to post most links, right?)
http://www.slippertalk.com/forum/showthread.php?t=2245&highlight=lance+sphagnum

 

John, I've put it in a plant flat and floated the flat in the pond. I put enough styrofoam sheets under the flat so just the base of the sphagnum moss was in the water. I suppose you could use a bucket. Use 'soft' water and no fertilizer. It's also done well in clay pots under the cool room benches.