Ashitaba -- a herb also known as "tomorrow's leaf" -- is native to Hachijojima island in Japan. The herb is used as a rejuvenating food that is thought to contribute to long life, and it's sought after for its many potential healing properties. The stems are filled with an edible yellow sap that contains high amounts of vitamin B12 and chalcones. Ashitaba leaves can be eaten fresh or dried to make tea. While it can be difficult to grow from seed, once mature, the ashitaba plant will be hardy and fast-growing.
Prepare the seeds for germination by soaking them in cool water overnight.
Fill a container with moist potting soil. Add the seeds and cover lightly with soil. Refrigerate -- below 4.5 degrees C (40F) for 30 days, being sure to keep the soil moist.
Fill seedling tray with moist potting soil. Transfer the seeds into the tray, barely covering with a layer of soil. Keep the flat moist and in a cool, protected area with plenty of light. The seeds will sprout within 15 days of sowing.
Ashitaba seedlings are very slow-growing. Allow 60 days before transplanting to the garden or individual pots. Transplant to well-drained soil and full sun to part shade. Water every other day.
Greenhouses are useful for keeping the seedlings protected from the elements while they grow.
Use a grow light as an alternative to sunlight if necessary.