ORGHPS Germination Guide: Sow immediately, Either the viability of these seeds is short or the species propagates best with fresh seed. Stored seed might be coaxed into germination with temperature cycling and patience. * sow in autumn in 1/2 seed mix, 1/2 grit, - don't prick out as they will die; leave for 2 years in pot in which they were sown; plunge pot in sand bed after germination

Source: Ontario Rock Garden & Hardy Plant Society