Dear All; This spring on a visit to the gorgeous Denver Botanic Garden, I saw plants of Sisyrinchium macrocarpum growing like they were perennials. Usually yellow flowered S. American Sisyrinchium are totally tender for me in Zone 5. Panayoti K. confirmed they were reliably hardy and pointed me to a Denver Nursery where I bought a couple and then planted them outdoors. Even after our recent 19 degree overnight low, they look OK. Anyone else have experience with Sisyrinchium macrocarpum in a colder climate and any comments on hardiness in general? The PBS wiki has a picture growing in Harry Hays' garden at: http://pacificbulbsociety.org/pbswiki/index.php/… Thanks Jim W. -- Dr. James W. Waddick 8871 NW Brostrom Rd. Kansas City Missouri 64152-2711 USA Ph. 816-746-1949 Zone 5 Record low -23F Summer 100F +