Pre-treatment: Seeds should be sown into cone-tainers filled with Sunshine #1 (a soil-less peat-based media) amended with micro-nutrients (Micromax) and a slow release fertilizer (Osmocote 14-14-14). The flats of cone-tainers should be covered with poly-ethylene bags and placed in a walk-in cooler (35-40 degrees) for 90 days. For a western Washington ecotype, 6 weeks of cold moist stratification and cool germination temperatures are recommended. For the Palouse ecotype, extended cold, moist stratification is needed. Seed can be sown directly in the field in late fall in a firm, weed free seedbed. Seed should be lightly covered to a depth of no more than 1/8 inch.

Establishment: All plant parts, including seeds and capsules, are poisonous and should be handled with diligence and care. The Palouse phase is mostly var. gramineus. Wetland indicator status is FACU (US Fish and Wildlife Service 1988).

Source: npn.rngr.net