The Iowa-based Seed Savers Exchange will celebrate another year of growing and perserving rare “heirloom” seeds and plants at its Heritage Farm north of Decorah. Founder Kent Whealey says it’s been an “incredibly busy” summer so far.Whelley says they maintain a “vast” collection of heirloom seeds, about 24,000 varieties, and the gardens to grow them all cover 23 acres, plus he says they’re in the middle of building a new visitors center. Every year the farms are planted with the old flowers, vegetables and other plants to re-produce at least ten-percent of the seeds that are carefully preserved and sold through the organization’s catalog. Whealey says it’s not only a lot of work, it’s a lot to keep track of.Kent and Diane Whealey began Seed Savers when her dying grandfather gave them seeds from a morning-glory vine and tomato plant brought from Bavaria. Realizing the plants were unusual, they joined with friends to preserve old-fashioned and diverse lines of cultivated plants to keep them from dying out. Though the aim of the Seed Savers is keeping genetic diversity alive so varieties of tomatoes, roses, and thousands of other plants aren’t reduced to a few strains, Whealey says the organization hasn’t heard from any genetic researchers doing DNA work. This weekend the farm hosts its annual convention for a few hundred of the the thousands of members worldwide. The keynote speaker will be an author and Amish gardener from Ohio and members will camp, take garden tours, enjoy live music and barn dances this weekend. It’s the 29th year of the Seed Savers organization and catalogs and information are on their website at www.seedsavers.org