Fourteen years ago, at the age of 17, Jere Gettle put together his first list of heirloom seeds and mailed it to 550 gardeners. Now he oversees a veritable empire consisting of the Baker Creek Heirloom Seed Company, the Bakersville Pioneer Village complete with seed store, bakery, restaurant, jail, herbal apothecary, music barns with monthly festivals and more in Missouri, and the Petaluma Seed Bank in California, which opened last spring. Most recently he bought the Comstock, Ferre…