Heirloom tomatoes are treasured by gardeners and chefs alike. Not only are they available in an array of unique colors, shapes and sizes, but many people believe that growing "old fashioned" open-pollinated tomatoes is an important way to preserve our agricultural heritage while also moving towards more natural foods instead of commercially available hybrids and genetically modified vegetables.
Heirloom tomatoes are open-pollinated varieties that are at least 50 to 100 years old. The seeds were traditionally passed down from one generation to another and many are named for the family that originally grew them. While some heirloom tomato varieties from yesteryear have become extinct, organizations such as the Seed Savers Exchange work hard to preserve rare and hard-to-find tomatoes. In recent years heirloom vegetables, especially tomatoes, have increased dramatically in popularity.
While grocery store tomatoes are generally limited to red beefsteak, paste and cherry varieties, heirloom tomatoes come in an endless parade of shapes and sizes. They can be white, yellow, red, orange, green, purple, striped and multicolor. Some have smooth skin while others such as Costoluto Genovese are ruffled and ribbed. Others such as the popular and coveted Marianna's peace look like standard beefsteak tomatoes, but their exquisite flavor once garnered a fee of nearly $25 for half a dozen seeds. Silver fir tree tomatoes are unique because of their foliage, which has a silver-gray shine and delicate, almost lacy leaves.
Because of their increasing popularity, many of the more common heirloom tomato varieties such as brandywine and stupice seeds and plants, can be found at nurseries and garden centers. However, many gardeners opt to buy seeds from specialty seed catalogs because they afford such a diverse and eclectic selection of varieties. Seed Savers Exchange has a public catalog that offers both seeds and transplants in addition to thousands of heirloom varieties in their annual yearbook, which is available to those who join their organization. Another way to obtain heirloom tomato seeds is to simply purchase heirlooms at a farmers market and save the seeds to plant the following season since they will grow true to type.
Most heirloom tomatoes are indeterminate, meaning that there is not a limitation on how large that the plant will grow.There are exceptions to this rule, such as Rutgers, which is determinate. However, most heirloom tomato varieties will need to be caged or staked for additional support. They should be planted in slightly acidic, well-drained soil and watered often, especially in extremely hot weather. Heirloom tomato plants will benefit from having a layer of mulch, compost or straw on top of the soil, both to help retain moisture and to provide additional nutrients. It is a good idea to plant an assortment of heirloom varieties that are early, mid and late season to ensure that there are fresh, homegrown tomatoes throughout the season.
Most people who grow heirloom tomatoes feel that their taste, appearance and natural diversity make them worth growing. However, heirloom tomatoes do have a few drawbacks. Many do not produce an abundance of fruit. Others are thin skinned, which means that the fruit has a tendency to be soft and the tomato may not have a long shelf life. For this reason, many types of heirlooms are not appropriate for commercial growing or supermarkets. Certain varieties are prone to cracking and others do not have as much resistance to disease as hybrids.