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What is an Heirloom Tomato?
An heirloom tomato is an open-pollinated variety that has been passed down at least 50 years through several generations in a family, ethnic, religious, or tribal group, or was commercially introduced before 1940.
Some tomatoes now marketed as “heirloom” are actually a cross between two different heirlooms (crossed on purpose or by nature), or are a cross between an heirloom and a hybrid tomato. The cross is then stabilized over several generations so they become open-pollinated.
What does open-pollinated mean?
Seeds from an open-pollinated variety produce offspring that are identical to the parent. With a little care to prevent cross-pollination, seeds can be saved that will produce identical tomatoes year after year. Seed saved from a hybrid variety or from cross-pollination will not always grow true to type.
While all heirloom varieties are open-pollinated, not all open pollinated varieties are heirlooms!
What is the history of heirloom tomatoes?
The tomato is native toMexico and Central America where it was cultivated by the Aztecs and Incas as early as 700 AD. It was introduced to Spain in the 16th century by the conquistadors and soon spread to Portugal and Italy, then later into Europe. It wasn’t until the mid 1800’s that the tomato became a staple in the kitchen gardens of the U.S. , although some Native American tribes and the Creoles of New Orleans already had a long history of its use.
During the next 100 years tomatoes were grown both at home, and by farmers who provided fresh tomatoes for the local markets. As new varieties were developed, seed companies often dropped older varieties from their catalogs. Unless families saved seeds from their favorite variety, the seeds became difficult to find.
After World War II, major developments were made in our highway and railroad systems. The ability to ship produce great distances increased the desire for tomatoes from warmer regions with longer growing seasons. The fragile but tasty tomato of the day was not a good shipper, so major hybridization programs were started to breed a tomato of uniform size and shape, and with a thicker skin to withstand shipping. The hybridization goals were expanded over the years to develop a brighter red color, develop varieties that ripened at the same time, develop adaptability to mechanical harvesting, and develop resistance to diseases and pests. Flavor was not a major consideration in the breeding programs.
Consumers complained for years that market tomatoes, and even the hybrids available to home gardeners, had lost their flavor. Interest arose in reviving the tasty old varieties to plant in home gardens. Some sources claim that over 80% of the varieties available in 1910 are now extinct and that until about 10 years ago most of the old varieties were in private collections. With the increased interest in old varieties, seed saving organizations with seed banks became popular and seed companies began growing “heirloom” seeds for specialty catalogues. As availability of heirloom seeds increased, small farmers began growing heirloom tomatoes for local farmers markets.
The selection of heirloom seeds available to the public is constantly expanding. Each wave of new immigrants to the U.S. brings their favorite seeds adding to the collection of traditional varieties grown by Native Americans, Mennonites, and Amish. Recently, there have been imports of heirlooms from Russia, Germany, Italy, France, and Czechoslovakia. There are new ethnic “finds” each year.
Why grow heirloom tomatoes?
Superior flavor: sweet, tart, acidic, juicy, or just “old fashioned tomato taste”.
Color variety: purple, pink, yellow, orange, dark maroon, green (when ripe), striped, marbled, and red. Many of the varieties grown at the turn of the 20th century did not produce the familiar round red tomato!
Unusual shapes and sizes: pear shaped, round, or lobed fruit; sizes ranging from a currant to a two-pound whopper.
Longer ripening season: many heirlooms have a long harvest season, unlike some hybrids that were bred for a heavy crop to ripen at the same time for ease of commercial harvest.
But there may be challenges: depending on the variety, some may be less reliable from year to year, have lower yields, start bearing later in the season, have wild vines that need sturdy support or pruning, fruits that develop cracks in the heat, or produce plants with less disease resistance. Some varieties are outstanding in one climate zone yet are disappointing in another. Experiment, find out what grows well in your area, and consider growing more than one variety for insurance.
Can you save the seeds?
Yes. But you need to take some precautions to prevent cross-pollination from other tomato varieties nearby or the seeds may not produce the tomato you wanted.
If you grow more than one variety of tomato, they should be planted at least 20-25 feet apart. In addition, a tall barrier crop (corn, pole beans, fruit trees, etc), or a continuous pollen-producing crop (squash) should be planted between varieties to distract the bees. These precautions will prevent most wind caused cross-pollination, and cause bees to visit only one tomato variety at a time before returning to the hive to clean off their collected pollen.
Save seed from healthy plants with the best fruit quality. Pick the fruit when ripe, scoop out seeds and pulp into a bowl with a little water then leave to ferment for 4 days (no longer or some heirlooms will begin to sprout). Separate out seed from pulp, rinse the seeds, then dry them on paper towels or a screen in a warm, dry place with good air circulation (try outdoors on warm summer or fall days). After 5-7 days, place seeds in airtight containers (plastic film canisters are good) and store indoors in a dark, cool, dry place. If properly stored, seeds should remain viable for 3-5 years.
Sources of information:
McCormack, Jeff. Isolation Distances for Tomatoes. Southern Exposure Seed Exchange.
Seed Savers International
Territorial Seed Company
Vegetarians in Paradise
Watson, Benjamin, Taylor’s Guide to Heirloom Vegetables, Houghton Mifflin Co., 1996
Compiled and written by Cathy Coulter, UCCE Master Gardener, Sacramento County