Two entrepreneurs are hoping to take gardening back to a time when an abundance of plant diversity was the norm. Matthew Hoffman and Astrid Lindo grow, source and sell seeds of rare and heirloom edibles. What's amazing is 100 years ago, everybody saved their own seed," Lindo said. By 1983, the 408 varieties of peas cultivated on American farms some 80 years earlier had dwindled to 25. Sweet corn saw a drop from 307 to 12 varieties. Hoffman undertook intensive training in New Mexico at the first-ever seed school taught by Bill McDorman, one of the veterans of the contemporary North American seed-saving movement. His enthusiasm was infectious; within a few months, Lindo decided to ... immerse herself in the fledgling business. The couple talked with experienced seed growers and farmers, researched catalogs, and scanned gardening forums and blogs online. And then they dug in and began growing their own seed. McDorman, director of Native Seeds/Search, a Tucson organization focused on conserving the genetic diversity of crops ... is effusive in his praise of the couple. "These young kids are way smarter than we were," he remarked. "Matthew and Astrid are indicative of what's coming, a whole new wave." The couple have ... a lively Twitter feed, a blog and a Facebook page as well as a YouTube channel with instructional videos on seed-saving techniques. The company also donates seeds to school garden programs, urban garden programs and correctional facilities.