Propagation protocol for rock evening primrose ( Oenothera caespitosa Nutt.)

Rock evening primrose (Oenothera caespitosa Nutt. [Onagraceae]) is readily grown from seeds. Mature capsules are collected between late summer and early fall. Seeds are removed from capsules by drying them for 4 wk in paper bags. Any capsules that have not yet opened on their own after drying can be opened manually. Seeds must be stratified for about 120 d to ensure germination. Seedlings can be grown to sufficient size in 1 y for outplanting using a standard medium and fertilizer.