There are many hundreds, perhaps thousands, of distinct garlic cultivars. Some garlics in circulation may have different names for the same genetically identical garlic. Many may be genetically distinct, but only slightly different from one another. Still others may differ considerably from one another. A relatively recent tool, molecular analysis of garlic has shed light on the differences among garlic cultivars. Our understanding of garlic’s genetic diversity has increased dramatically with the increasing sophistication of these analytical tools. Earlier studies relied on isozymes to assess genetic differences. More recent studies employ various methods of DNA analysis to reveal garlic’s genetic diversity.
Most garlic cultivars fall into genetic clusters---groups of garlic cultivars that share genetic similarity. These groupings are also associated with shared observable characteristics. With our current understanding, there are some eleven of these horticultural groups. As our understanding of garlic increases with subsequent DNA analysis, it is likely that these groups will change somewhat and there will likely be additional groups.
The horticultural groups are substantially those described by garlic grower and keen observer Ron Engeland in 1991 and 1995, with some updating and revision. Most of these groups are widely, though not universally recognized and have been substantially validated by molecular studies, though some of the groups have not been adequately represented in the studies. Subsequent molecular research will likely further refine the horticultural groups presented here, but in general, if you encounter an unknown cultivar, it will likely belong to one of eleven horticultural groups, Artichoke, Asiatic, Creole, Glazed Purple Stripe, Marbled Purple Stripe, Middle Eastern, Porcelain, Purple Stripe, Rocambole, Silverskin, and Turban. Not every cultivar, however, fits neatly into the existing horticultural groups. These outliers add to the enjoyment of exploring garlic’s genetic diversity.
These horticultural groups reflect the broad diversity of the species. Cultivars in the Purple Stripe group are genetically the closest to wild garlic and garlic’s ancestral roots. Some were only recently collected from the wild. Many of the Rocambole cultivars offer the unique rich “sweetness” that, along with their easy peeling properties, makes them a favorite in the culinary world. Some Porcelain cultivars are especially high in sulfur compounds healthy to the body, and their huge cloves make for quick work in the kitchen---and so on.
Not unexpectedly, differences within horticultural groups are generally more subtle than the differences among horticultural groups. If you are able to do so, try growing or sampling at least one cultivar from each of the horticultural groups. This is a fine way to begin exploring the world of garlic. Most specialty growers offer at least one cultivar in most of these groups.
Each garlic horticultural group offers unique properties worthy of exploration. As you venture along in your journey, you will come to your own discoveries and develop your own favorites.
Artichoke cultivars are among the most productive and least problematic. They are among the earlier ready for harvest, readily develop very large bulbs, and adapt to a wide range of growing conditions and soils. Most rarely bolt, if ever, so the plant directs more of its energies to bulb development rather than the reproductive mechanisms. Bolting cultivars often require removal of the flower stalk to achieve the largest bulbs and greatest productivity. From the standpoint of a large-scale commercial grower, an easily grown, heavy producing garlic that does not need the additional labor-intensive step of scape removal is highly desirable. This quickly rules in Artichoke garlic and rules out all bolting hardneck garlic. Artichoke cultivars are by far the most commonly favored and grown commercial garlic. Most of the garlic in the supermarket is from the Artichoke group. The flavors are familiar, but have a bit of a vegetative element rather than the richer deeper characters of some of the other horticultural groups.
Asiatic cultivars are readily identifiable by their distinctive umbel capsule (flower head surrounded by a protective bract). When fully developed, the capsule has an exceptionally long beak that is broad and hollow for a substantial portion of its length. The bulbils (miniature bulbs in the umbel) are also distinctive. They range from large to huge in some cultivars, and are often very dark reddish purple. For some cultivars, the umbel capsule may have as few as two to four bulbils. If planted, the bulbils are large enough to produce a small multi-cloved bulb at harvest. Unlike most bolting cultivars, Asiatics do not require scape removal (flower stalk)to produce large, normally sized bulbs, though scape removal may yield slightly larger bulbs in some growing conditions. The scape is typically short and drooping rather than strongly coiling. The flavors range from mild in some cultivars to spicy and intense.
The Creole group is well suited to hot southern growing climates and is tolerant of early season heat and drought. Many of the Creole cultivars in circulation in the
United States originated in . Creoles thrive in hot, southerly climates. They do not grow as well in more northerly climates, typically yielding small bulbs. Even in ideal growing environments Creole bulbs are only moderate in size, but their quality more than compensates. Creole cultivars typically bolt in the temperate growing regions of Spain North America, but the bolting impulse is not as insistent as it is with the strongly and steadfastly bolting cultivars such as Purple Stripes or Rocamboles. Creoles are very beautiful. The clove skins are very vividly and deeply colored, in a range of shades of red and purple. Creoles store exceptionally well. They have a reputation as “sweet” tasting garlics, particularly after lengthy storage, though some cultivars can be quite hot as well.
Glazed Purple Stripe
Glazed Purple Stripe cloves are generally more squat and fewer per bulb than Purple Stripes, but more numerous than Marbled Purple Stripes. Glazed Purple Stripes are strongly bolting hardneck cultivars. The name, Glazed Purple Stripe, is a good descriptor. The bulb wrappers have a glazed, matte metallic appearance. They are silvery-purple with occasional gold tones. The clove skins are smooth and shiny with purple blush over a tannish background. The bulb coloration is certainly attractive, and these are very fine culinary garlics as well. My own preference leans more toward full-flavored garlics, and for that reason, the mild flavored Glazed Purple Stripe cultivar Red Rezan is less of a favorite, though others may find it a perfect match. I am quite taken with Vekak, a newer addition to the group, which is neither vegetative or sulfurous, but offers rich, rounded garlic flavor.
Marbled Purple Stripe
Marbled Purple Stripe bulbs are purple striped and marbled or dappled with purple. The cloves are large, squat, and fat. They are tan to brown and sometimes have varying degrees of dark purple coloration. Because of their size, there are fewer per bulb of an equivalent size than Purple Stripe, but generally more than Porcelain. The cloves are arrayed in a single layer around the flower stalk. The leaves are relatively wide, and the plants are very vigorous and tall. Marbled Purple Stripes are strongly bolting cultivars. The thick scapes curl dramatically before straightening and becoming erect, reaching up to 6 ft. (1.8 m) for some cultivars when grown under optimal conditions. The scapes generally must be cut or bulb size will suffer. Marbled Purple Stripes store reasonably well, and the large cloves are relatively easy to peel. The taste can be quite hot raw. Sautéed, the taste can be somewhat more sulfurously garlicky and not as nutty and rich as Purple Stripe cultivars. After cooking, some cultivars can taste mealy and a bit bland, though the best more closely approximate Purple Stripes in flavor and character.
Perhaps productive in their native environments, the Middle Eastern cultivars are as interesting as they are ill-suited for garlic growing in most of the North American Continent. You are unlikely to find them at your local farmers market or even from specialty growers. The relative smallness of the plants has made it difficult to assess their morphological characteristics with the assurance that the cultivars have fully expressed themselves. The multiple clove layers and numerous cloves might suggest a kinship with the Silverskin group, though the cloves are more separated, with rounded sides and an inner surface that is curved, but not flattened or concave as is typical of Silverskin cultivars. The small bulbs and numerous tiny cloves do not recommend them as a market garlic, though they are intriguing to the dedicated aficionado.
Porcelains are impressive, tall, statuesque plants, reaching up to seven feet. The bulbs are impressive as well. They are large and typically all white, hence the name Porcelain, although purple or copper streaking may sometimes appear depending on growing conditions and cultivar. Porcelain bulbs generally have four to six cloves arrayed in a single layer around a sturdy flower stalk. Since the cloves are so few and the bulbs are so large, the cloves are exceptionally large as well. The cloves are fat, but more elongated than Marbled Purple Stripe cloves. As a group, Porcelains have among the highest yields of allicin, the sulfur compound most associated with garlic’s therapeutic benefits. The trade-off is that they can taste a bit sulfurous and unsubtle. Porcelains have intensity, but most are less generous in flavor complexity and depth than Purple Stripes, or even Marbled Purple Stripes. Porcelain cultivars are very cold hardy, and have been a mainstay for many Canadian garlic producers. Porcelains are more adaptable than many other strongly bolting cultivars, and they grow reasonably well in warmer southerly climates. Like all strongly bolting hardneck cultivars, the scape usually must be cut or else bulb size will suffer as the plant’s energies are directed away from the bulb to produce the thick towering flower stalk and bulbil-filled umbel. Porcelains are the largest garlic plants and have the largest cloves, but the bulbils are the smallest of any garlic cultivar. Porcelain umbels are filled with up to a hundred or more rice-size bulbils.
Purple Stripes are the earliest ancestral garlic forms still existing on earth. Genetically closest to the origins of the species, Purple Stripes are the ancestors and antecedents of all other garlic cultivars. Some Purple Stripes, with assistance, remain capable of sexual reproduction and the production of true seed. Purple Stripes would be inherently special even if their primal origins were their only notable feature, but they are also splendid culinary garlics. In general, the taste of Purple Stripe cultivars is strong, complex, and richly garlicky, without being overly sulfurous. They do not have the sweetness of Rocamboles, but some of the best may be even more characterful. Purple Stripes are named for their vivid purple coloration and striping on the bulb wrappers and clove skins. The cloves are generally arrayed in a single layer around the flower stalk, though very large bulbs may have inner cloves. For a similarly sized bulb, the cloves are more numerous and thus somewhat smaller than Rocambole cloves and considerably smaller than Marbled Purple Stripe cloves. Purple Stripe cloves are tall and crescent shaped with somewhat angular edges and an elongated tip. The plants are somewhat delicate in appearance compared to Marbled Purple Stripes or Porcelains. Purple Stripe scapes coil vigorously before uncurling and becoming erect. The umbel capsule contains numerous small to medium-sized purplish bulbils and numerous pink to purple colored flowers. Befitting the groups ancestral origins in the harsh environment of
Central Asia, Purple Stripes need exposure to cold to grow well and develop large bulbs, though they can still produce reasonably well in some southern regions. They are strongly bolting hardneck cultivars. When they bolt, Purple Stripes rapidly divert their energies to the reproductive structures and away from the bulb. Bulb size suffers considerably if the scape is left uncut.
For many, Rocambole is synonymous with hardneck garlic and culinary supremacy. Rocamboles are among the most widely known and grown hardneck garlic cultivars. Back in the Dark Ages, when I thought that garlic was just garlic without distinction, I purchased a few heads of garlic at a farmers market. The garlic was the Rocambole cultivar Spanish Roja. I tried it and I knew then that all garlic was not the same. In the views of many, Rocamboles are the finest tasting garlic of all. The best have a rich, deep, complex flavor palate. Rocamboles are “sweet” as opposed to aggressively sulfurous, and they are devoid of vegetative overtones. While Rocamboles certainly have garlic’s heat when eaten raw, they are relatively moderate in that regard, and the heat is balanced by a fine depth of character. Rocamboles are especially good when raw garlic is called for, such as for crushing and mixing with vinegar or lemon and olive oil for salad or vegetable dressing. Unfortunately, Rocamboles have a few practical downsides. They store poorly and they are more demanding of growing conditions. Rocamboles require a period of winter cold to grow well, and they may not grow at all in southern climates with warm winters and springs. Rocambole cloves peel exceptionally easily, which is part of the reason for their short storage life. The scapes curls more tightly than the scapes of any other garlic horticultural group, sometimes completing as many as three complete curls before straightening and becoming erect. As with most strongly bolting cultivars, the scape should be removed or else bulb size will likely suffer. The Rocambole spathe is distinctive, turning from yellowish to whitish at maturity, in contrast with the spathes of other horticultural groups, which remain yellowish. The plant’s leaves are broad and closely spaced. The bulbils range in size from medium to large. The plants are not particularly tall, but the wide, closely spaced, blue-green leaves give a substantial look, topped by the drama of the tightly curling scape.
Silverskins are among the longest storing cultivars. If storage conditions are favorable, well-grown bulbs can be stored for up to a year or more. On the negative side, the taste can be hot, sulfurously aggressive, a bit acrid, and lacking in nuanced complexity. Silverskin cultivars are generally quite productive and tolerant of a wide range of growing conditions, though they grow best where the growing season is long and the winters are mild. Like Artichoke cultivars, Silverskins are generally non-bolting and softneck, though a portion of the crop of some cultivars may routinely bolt in more northerly regions. Artichoke cultivars tend to be larger with a flattened bulb shape. Silverskins tend to have more of a teardrop shape and are generally smaller. Comparing similarly sized bulbs, Silverskins have more cloves than any other horticultural group. The cloves are arrayed in multiple layers. Many of the inner cloves are tall, slender, and small. The outer cloves are relatively large, flattened on the interior side, tallish, with rounded corners and a graceful curvature that helps form the teardrop shape of the bulb. Conversely, Artichoke cultivars tend to have fat, blocky outer cloves with more squared sides and angular edges. Silverskin bulb wrappers are white, but may have yellow or tan veining. The bulb and clove skins adhere very tightly, contributing to exceptional storage longevity but more difficulty in peeling. Silverskin leaves are narrow and blue-green. The thin sturdy leaves remain pliable after drying. The leaf characteristics, combined with the compact, teardrop-shaped bulb, and long storage ability, make Silverskin cultivars the chosen garlic for braiding.
The group is named for the flattened turban shape of the umbel capsule. Turban cultivars are among the first ready for harvest; have the shortest dormancy, and thus the shortest storage ability; and are the first to sprout after planting. Everything about them is quick and early. Turbans have been compared to the garlic world’s summer apple. Their taste is typically simple and direct. After many weeks of gleaning the last of last season’s harvest in search of garlic that is not too dried up or sprouted, the juicy fresh cloves from the newly harvested Turbans are quite welcome. Turban plants do not look very robust. They are not very tall, and their medium-sized leaves are spaced relatively far apart. As harvest approaches, the plant may bend at ground level and fall over. In spite of these weak-kneed histrionics, most cultivars readily produce large bulbs. The bulb wrappers are typically heavily blotched or striped with purple. The cloves are usually arrayed in a single layer. Because they are fairly numerous on large bulbs, the cloves are more slender than squat and fat. They are also more rounded and less angular than the cloves of other cultivar groups. The clove skins are typically tan to satiny pink, but may have purple, red, or brown tones in some instances. Turbans are weakly bolting and may sometimes refuse to bolt, particularly in more southerly regions. The scapes droop, but do not curl. The umbel capsule has a relatively short beak and contains numerous small to medium-sized bulbils. Unlike most horticultural groups, Turban bulb size is not greatly affected if the scapes are left on the plant.