I'm sold on Allium species for both green roof and living wall plants. Hardy, evergreen, tolerant of inundation and tolerant of drought, these hardy plants form the backbone of many non-irrigated green roofs. MetroVerde's bonsai-ed variety is an especially hardy variety - grown in a greenhouse with limited watering - typically les than 1/4 inch per month for over a year. This picture I took today at University of Florida - we have a panel there - as we've written about before - and the system is non-irrigated, been in a harsh test area for over a year now - and the Allium species are growing strong! Call Kevin with your low weight, extensive, non-irrigated green roof questions. 904-294-2656.