Have a green thumb? Stop by St. Mark's Presbyterian Church (3809 E. Third St.) on Saturday, March 19, from 10 a.m. to 2 p.m. for the bi-annual Tucson Organic Gardener's Spring Garden Fair. The fair will gather over 20 gardening vendors and organizations and admission is free. Seeds, starts, soil and fertilizer will be available along with arts and crafts, natural beauty products, native plants, and tools for every gardening level. More information at www.tucsonorganicgardeners.org.