As the sustainable agriculture movement gathered steam in the late 1990s, heirloom tomatoes made a comeback after being in the shadow of hybrids since World War II. Heirlooms---in their hundreds of forms---preserve the genetic diversity of this favorite garden vegetable and offer better flavor than hybrids. A chemist in North Carolina named Craig LeHoullier and a retired professor named Carolyn J. Male, who raises more than a 1,000 heirloom varieties in upstate New York, have led the way in categorizing heirloom tomato types.
LeHoullier and Male divide heirloom tomatoes into four types. These are the tomatoes "that most people want to grow," writes Male "100 Heirloom Tomatoes for the American Garden." Immigrants to the United States in the late 1800s and early 1900s from Bulgaria, Germany, France, Poland and elsewhere carefully bought these seeds from home to the New World, where farmers and home gardeners kept the lines going. Examples include Eva Purple Ball from the Black Forest region of Germany, Marizol gold from Germany and Myona from Italy. American family heirlooms include Aunt Ginny's Purple, Mortgage Lifter, Red Brandywine and Kellogg's Breakfast.
Seed companies introduced commercial heirlooms prior to 1940, when hybrid tomatoes introduced by the Burpee Seed Co., including its smash hit Big Boy tomato, began to dominate the market. LeHoullier and Male searched the U.S. Department of Agriculture seed collection to resurrect numerous varieties, including Paragon and Trophy, dating from 1870, Favorite (1883), Redfield Beauty and Optimus (1885) and Alpha Pink (1915). They listed these varieties with the Seed Savers Exchange, a seed bank and seed-sharing service in Decorah, Iowa. Male notes that Redfield Beauty, Paragon and Optimus remain personal favorites for their quality flavor.
Some heirloom aficionados cross two heirlooms or an heirloom and a hybrid to create new tomato types. The hybrid seed needs to be grown over three to 10 years to convert from a hybrid to an open-pollinated form with consistent form and desired traits. Examples include Banana Legs, Green Grape and Green Zebra, created by Washington state plant breeder Tom Wagner.
When cross-pollination occurs by accident rather than design, the result is a mystery heirloom, according to Male. Mystery heirlooms, such as OTV (off the vine) Brandywine, result from natural cross-pollination of other heirlooms, in this case, a Yellow Brandywine with an unknown red parent that produced a "magnificent" red beefsteak tomato.