Sorry, I meant Trillium ovatum. Trench bed: I think very similar to "rain gardens". Do a google search for many examples. The idea is water from rain is directed into the bed and protected from evaporation by wind. The key is that it is below grade, the rest is up to your imagination. Travis Owen Rogue River, OR amateuranthecologist.blogspot.com http://www.pacificbulbsociety.org/