Lifelong gardener Nan Sterman has lived many lives as a scientist, an instructional designer, and a journalist with bylines in Sunset and the Los Angeles Times, among many others. She’s the host of A Growing Passion, a TV show about gardening, an international speaker, and the leader of a Facebook group with tens of thousands of members. Now, at Nan Sterman’s Garden School, she provides her students with a simple approach to starting seeds…