One reason to grow heirloom vegetables is simply that they are a taste of  the past. Many varieties, which had been prized and maintained for generations, have been lost in recent decades as fewer people save seed year to year. For many gardeners, saving an heirloom cultivar is a connection to their heritage.

Many gardeners grow heirlooms that have superior flavor. Heirloom varieties that have been selected for taste and tenderness through several generations are often tastier than cultivars that have been selected for ease of shipping, uniform appearance or ability to grow well throughout the country.

When gardeners save the seed of the best-tasting, best-performing plants in their gardens each year for a number of years, they gradually select their own special cultivars. Those selections will be suited to their own growing conditions and tastes. Open-pollinated seed that has been grown and harvested for generations in a region or microclimate becomes adapted to that area's soil, climate and pests.

Many people grow and save old cultivars because they save a lot of money by avoiding the purchase of new and expensive hybrid seed each year. Hybrid seed will not produce similar plants when saved from year to year. Another vital reason to maintain heirlooms is to keep their genetic traits for future use. When old varieties of food crops are not maintained, the gene pool grows smaller and smaller. This may lead to increased disease and pest problems.