Although known primarily to Americans as a flavoring in salsas and Tex-Mex cuisine, the tomatillo (Physalis ixocarpa) is a staple in Mexican diets and is eaten throughout Central America. Tomatillos, with many alternative names including Mexican husk tomato, jamberry, and tomate de bolsa, have been cultivated in Mesoamerica since pre-Columbian times and even dating back to 900 BC, but never achieved widespread popularity abroad except in the American Southwest. Indeed, tomatillos have long existed in the shadow of their larger, juicier cousin–Spanish explorers brought the tomatillo to Europe, where they enjoyed brief popularity before being eclipsed by the arrival of tomatoes.
Tomatillos have unique uses, however. They have a very tart, acidic taste that mellows when cooked, so after being lightly steamed they are used as a base for many sauces (they are essential to salsa verde), marinades, and stews. They add spice and zest to salads, casseroles, marmalades, and even fruit pies. They are a good source of vitamins A and C as well as niacin, and because of their unusual growing style—the tomatillo fruit grows encased in a paper-thin husk, or calyx—consumers can use more than just the fruit. In Mexico, the husks are boiled down and added to tamale dough and fritters to improve consistency, and to impart flavor to white rice. This decoction of the husks is also said in Mexico to treat diabetes.
Perhaps most importantly for Mexican farmers, tomatillos are very hardy, adaptive, and easy to grow. Like most plants in the solanaceae family—which includes eggplants, peppers, and tobacco— tomatillos can be grown in tropical, semi-tropical, or temperate regions. Their season usually stretches from May through October, during which the plants can produce impressive amounts of fruit. In addition, wild tomatillo plants often spring up in cultivated fields, and in some rural areas they are an important, if incidental, addition to income or diet.
Tomatillos are most often found canned whole in supermarkets, although the raw fruit can be found at many farmers markets or Latin grocers. Raw tomatillos are usually varying shades of purple or green, and their size ranges from an inch in diameter to plum-sized. After ripening and harvesting, tomatillos can be stored only when their papery husks are dry and clean, to avoid molding, so many growers pull up the whole plant and hang it upside down to dry the husks. When the husks are dry, the fruits can be stored for up to a month, much longer than most ripe fruits. This long storage life, plus its hardiness, opportunism, and flavor, give tomatillos great potential for growth in gardens around the world.
Laura Reynolds is a research intern with the Nourishing the Planet project.