Garlic is truly an international food, lending its flavor to a buffet of dishes from Szechuan stir-fries to Moroccan tagines, Argentinean chimichurri sauces, Italian pasta dishes, and more. The bulb owes its popularity to both its culinary uses and its health benefits—consuming garlic has been linked to reduced cancer risk and better cardiovascular health. Like so many foods, the garlic commonly found in the supermarket is sold not for its fine flavor but for its superior storage time. Growing garlic opens the door to a range of tempting possibilities, from bulbs wrapped in luminous pink-streaked wrappers (as the papery outer skins are known) to ones composed of mild, almost sweetly flavored cloves. Best of all, garlic is one of the easiest vegetables to grow. All one needs is a small measure of patience, waiting for the autumn-planted crop to ripen for a summer harvest.
A member of the genus Allium, which includes onions, shallots, leeks, and chives, as well as ornamental onions, garlic is an underground bulb (also called a head) made up of individual cloves; when you plant a clove, it matures into a bulb. Garlic is divided into two categories, hardneck and softneck, that differ in the size of the bulb, the number and size of cloves, color, hardiness, and storage qualities. Elephant garlic, which is the sort most often used for roasting, is actually a type of leek that has a mild garlic flavor.
Hardneck garlic (Allium sativum ssp. ophioscorodon) produces a stiff flowering stalk, called a scape, topped with bulbils (tiny bulbs) instead of seeds. A single cluster of 5 to 10 large cloves surrounds the hard stalk. Hardnecks are tolerant of cold weather and offer a range of flavors from mild to strong and spicy.
Softneck garlic (Allium sativum ssp. sativum) rarely produces a flowering stalk; the cloves are smaller than hardnecks and are arranged in overlapping layers. A single head may have 6 to 18 cloves or more. The soft, pliable necks are easy to braid into garlic "ropes." Softneck varieties are less cold-tolerant and therefore better suited to growing in regions with mild winters, but they do keep longer in storage than hardneck garlic.
"There are hundreds of variety names for garlic, but there are only 10 major types based on their genetic diversity," says David Stern, an organic farmer and the director of the Garlic Seed Foundation in Rose, New York. "Garlic varieties have been renamed many times as they passed among growers and gardeners, and as a result, many may be identical genetically." The 10 types or groups of garlic are rocambole, porcelain, purple stripe, marbled purple stripe, glazed purple stripe, Creole, Asiatic, and turban among the hardnecks; and silverskin and artichoke among the softnecks. The papery white garlic bulbs available in most grocery stores are artichoke-type softnecks.
Many garlic cultivars have names that indicate where they were traditionally grown or the color of their wrapper, including 'Oregon Blue', 'Chinese Pink', 'Chesnok Red', and 'Spanish Roja'. A study published in 2009 by David Stern with Gayle Volk, Ph.D., of the USDA's National Center for Genetic Resources Preservation in Fort Collins, Colorado, found that no matter what name a garlic cultivar had or which group it belonged to, the color of its papery wrapper and overall bulb size were highly dependent on where it was grown.
This fact helps to explain why so many different variety names exist for genetically identical garlic. It's also an argument for buying locally grown garlic, says Stern. If you buy garlic from a local farmers' market and plant the cloves, what you see at planting time is likely what you'll get when you harvest the bulbs.