Rhodiola rosea, also known as golden root and rose root, is an extremely cold-hardy plant similar to a large Sedum with yellow flowers and a thick root. In nature, it grows from sea level up to over 6,000 feet, usually in rocky soil, and each individual bears either male or female flowers. It has been used for centuries as a medicinal herb in Scandinavia and Russia, and has recently become popular in North America.
Sow seeds in fall or early spring. Mix potting soil with an equal amount of sterilized sand and fill a propagation flat (approximately 20 by 11 by 2 inches) with the mixture to within a half inch of the top. Press the mixture down firmly.
Mix the Rhodiola seeds with several tablespoons of sand and dust evenly over the surface of the flat. The seeds are quite small and difficult to plant individually.
Cover the seeds with a thin layer of sand or fine gravel, no more than an eighth of an inch deep. Water with a fine mist to prevent washing away of the seeds.
Place the flat in a sunny area, but make sure that the surface of the soil does not dry out before the seeds sprout. Germination can be quite low, but you should get enough seedlings to start your collection.
Transplant seedlings to 2-inch pots when they are half an inch high, and grow in sun to partial shade until the following year when they can be planted into an open garden bed--one with sandy, perhaps even rocky, soil. The plants dislike sitting in standing water.