Onions are one of the stalwarts of the kitchen. They are found in a wide range of cuisines and dishes, although they aren’t as common in the kitchen garden, in part because of their low prices at the supermarket. Heirloom onion varieties, however, can be difficult to get at the local grocery, so more gardeners and cooks are turning to growing their own, drawn by the rich, unique flavors and textures that heirloom onions offer.
Onions are widely cultivated members of the Allium, or onion, genus. This genus comprises 600 to 800 different species; botanists differ on the exact number. The perennial is known for its odiferous members that are largely found in the temperate Northern Hemisphere, though some species occur as far south as Brazil, Chile and Africa.
Typically the genus produces a single bulb, as in the case of onions; an aggregate of bulbs, such as in shallots; relatively clustered on a rhizome (root), such as chives; or loosely borne on the end of stolons, as in wild leeks (ramps).
Most, if not all, members of this genus are edible, although only a relatively small number of its members are cultivated for food. These include onion, garlic, shallots, potato onions, leeks, chives, garlic chives, curly chives, scallions (typically Welsh onions or Japanese bunching onions), or top-setting or Egyptian walking onions.
About 30 species have been used for food, with half this number cultivated. Given the edibility and the taste characteristics present, there are many underexploited culinary possibilities for the home gardener. For more on growing onions in your garden, see Growing Onions the Easy Way.
Additional species are cultivated as ornamentals in both perennial borders and alpine gardens.
Onions flower in a distinctive, variably rounded umbel. Some of the onion flowers form seed, while others form bulbils as in garlic or walking onions. Like grasses and orchids, onions are monocots; they have only one embryonic leaf in their seed. Their flowering parts are in threes and their veins parallel.
The onion genus is a member of the amaryllis family, which consists of only two species, both ornamentals.
This family is not the same as the large showy onion flowers we commonly refer to as Amaryllis; those are Hippeastrum. Amaryllis obviously had a better press agent than the alliums in order to get the whole family of veggies named after a member with a mere two species.
The origin of onions
The word ‘onion’ is derived from the Roman unionem, a colloquial word referring to type of onion and also relating to “pearl” and “unity,” presumably referring to its successive bulb layers. Ultimately, the word became oignon in French, as well as union in French and English, one of the antecedents of the modern word ‘union.’
The onion is a true biennial; it flowers and forms onion seeds in its second year of growth after a dormancy period. Onion is a cultigen, a domesticated crop created by people. The botanical ancestor and precise geographic origin of the onion remains unclear. Both western central Asia and the Middle East are considered its center of origin, from Iran to western Pakistan and Afghanistan. What is clear is that the onion is an ancient cultivated plant.
The earliest recorded history of onions comes from Egyptian tomb and pyramid decorations from around 3,500 B.C. Somewhat later, beginning in the Old Kingdom, onions were used as offerings and were depicted on offering tables.
They were used in preparation for mummification where they were evidently placed on several parts of the body, and onion flowers have been found in chest cavities. According to the Roman poet and satirist Juvenal, onions were worshipped by some Egyptian cult groups. There is evidence supporting cultivation in Sumer in the third millennium B.C., and they are mentioned in the Bible. It is likely they were cultivated much earlier, but there are no depictions or archeological remains to verify that.
The Greek historian Herodotus mentions that onions along with other crops were part of the foodstuffs used to feed laborers during the building of the pyramids at Giza, and nine tons of gold were spent for these supplies. Onions were commonly cultivated in ancient Rome in special gardens called cepinae, and they were supposedly used to rub down gladiators. Commonly cultivated in Greece, Theophrastus mentions several varieties based on where they were cultivated including Turkey, Greece and possibly Italy. Pliny in the first century discusses the history and cultivation of onions, mentioning six types of “onions” including shallots.
It is believed the Romans brought onions to Europe, certainly by the first century in Spain, although it took a long time for them to be fully adopted as a crop, especially in northern Europe. They were used sparingly in the early Middle Ages, and they only became popular in the late Middle Ages, entering Russia in the 12th or 13th century.
In the New World
Onions were one of the first crops brought to the New World, and were cultivated on the island of Hispaniola by Columbus’ crew in 1494. Twenty-five years later, Cortez supposedly saw the Aztecs cultivating onions, garlic and leeks. The Pilgrims were growing them by 1629; particularly the early colonists in Virginia.
Onions continued to increase in popularity in Colonial America, and, by 1802, seedsman Bernard McMahon listed seven varieties of onion along with other alliums. A hundred years later, the United States Bureau of Plant Industry Bulletin lists approximately 400 onion varieties, including 50 names for Red Globe. While most of these varieties are synonyms, among different seed companies there was clearly a great deal of interest in cultivating onions.
The Maule’s Seed Catalog of 1902 calls its onion seed the company’s “greatest specialty” and fully describes 22 varieties.
Heirloom onion varieties
One of my favorite heirloom onions is Red Wethersfield, or Wethersfield Large Red. Legend has it that it originated in Wethersfield, Connecticut, although the community seems to have been the primary center of its popularization by growers. It first appeared in catalogs as Large Red, listed by Hovey of Boston in 1834, and did not seem to appear in Wethersfield until the 1850s, when it became more or less continuously offered by Comstock Ferre Seed Co., which continues to offer it today.
The Large Red is a large, rounded to somewhat flattened red onion, highly productive, with good taste and reasonable keeping qualities. I cannot understand why this onion has not remained more popular — it is excellent. In my experience, it has a tendency to produce a higher number of double bulbs, which may be a product of various cultural conditions and could be a reason why it has not persisted commercially, although this is not a problem for the home gardener.
Another great red onion is Southport Red Globe, a fairly round, productive onion that keeps well into April — longer than the Wethersfield. Developed in Southport, Connecticut, it was introduced around 1870.
A “sister” onion to Red Globe is Southport Yellow Globe, also introduced in the late 19th century. It produces large yields of solid, long-keeping onions, though a small percentage are thick-necked and do not cure or keep well.
Another notable American 19th century variety is Early Yellow Globe, which seems to have disappeared from the commercial market. It is, as the name indicates, relatively early, globular and productive. A selection of it called New York Early has been maintained by Orange County, New York, growers and, while I have not grown it, it is considered superior to the original type. It is also commercially available.
A couple off non-American heirloom onion varieties are worth noting. Australian Brown, a yellow onion, was sent to the Ferry Morse Seed Co. in 1894 as Brown Spanish, and then renamed by Burpee in 1897. It has light, brownish-red skin, is rounded and slightly flattened, and keeps well. Ailsa Craig was introduced by David Murray in 1887 from Scotland in a cross between Danvers Yellow and Cranston’s Excelsior. It is a large 1- to 3-pound sweet onion, historically considered an exhibition variety due to its size. Its skin is a pale straw color. While productive, it is not a long keeper.
Highly flattened onions were well-known in the 19th century, and perhaps the flattest type is the Cipollini or Borettana, an Italian heirloom enjoying recent popularity in the United States. The onion is typically about 3 inches wide and 1 inch thick, making it quite distinctive and gorgeous when braided. The flesh is mild, and, under good conditions, it will store well. There are red, yellow and white fleshed forms. Be aware that modern hybrid varieties sold as cipollini are not the heirloom type. Cipollini in Italian literally means “small onion,” so its name may be applied liberally. With this onion you get more quality than quantity. Traditionally used for pickling, try them skewered on the grill or roasted.
If you search around, there are other heirloom onion varieties worth growing. Growing good onions is a long-term commitment; you’ll have to start your own seed as most of the heirlooms will not be available as sets or seedlings.
Ethnobotanist and former director of the Eastern Native Seed Conservancy, Lawrence Davis-Hollander gardens, cooks, and — at a nearby preserve — watches bald eagles and seasonal wildflowers.