From seed:  Seeds respond well to at least two months of cold stratification and perform especially well when fall sown outdoors in containers. Supplemental watering during their first summer helps young plants establish strong roots. With a bit of care, seedlings can grow quickly enough to be transplanted within a single growing season. They may begin to flower as early as their second year, and once established, are long-lived and low-maintenance. Transplants easily.  Dies back by early summer, leaving no trace until the following spring!