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 @ 20°C. If seed does not germinate within 3 months, try 4°C for 1-2 months, then 20°C again. Requires light or the seed is very fine. Surface sow and expose to light. Germination if successful only when GA3 is used. * avoid pricking out individually, transplant seedlings in clumps

Source: Ontario Rock Garden & Hardy Plant Society