Unlike the single-season hybrid seeds sold at most garden stores, open-pollinated seeds allow you to save the seeds from mature plants to cultivate the following season. It is, of course, the traditional regenerative method of horticulture used since the dawn of humanity and every gardener who cares about biodiversity should naturally want to save seeds from each successive harvest in order to replant stronger, more locally-adapted plants that help sustain the environment.
Dozens of companies, part of a blossoming heritage seed movement now specialize in heirloom and open-pollinated seeds. The following online catalogues provide a bounty of both seeds and sowing-tips for the savvy heirloom loving urban-gardener.
NativeSeeds/Search provides access to a wide range of heirloom vegetable seeds including those introduced to the New World by the Spanish and those traditionally used by Native Americans in the Southwest.
Redwood City Seed Company is involved in the restorative cultivation of native wildflowers and a good source of heirloom pepper seeds as well as tips on proper pepper propagation.
Seeds of Change has a helpful website offering good descriptions and photos of every plant variety they sell. Suitable quantities for home gardeners and small farmers are available for a wide array of open-pollinated vegetable, herb, and flower seeds.
Territorial Seeds maintains a well organized website offering an excellent selection of short-season vegetables as well as a valuable section devoted just to growing instructions.
Sierra Seeds is a small, regional seed company based in Nevada County, California. Providing access to regionally-adapted seeds that thrive in the Sierra Foothills of Northern California. They also provide economic incentives and on-the-ground support to a cooperative circle of seed growers, developing outreach and educational programs to support seed production in their region, with an emphasis on crop improvement for organic agricultural systems.