Although popular in American horticulture, onions have a fascinating history.
Due to their small size and compostable tissues, it’s difficult to determine where onions originated. However, many  believe they came from central Asia, Iran, or India. People discovered and began consuming wild onions as a staple in their diet thousands of years ago. Over time, the wild onions became domesticated and were popular because they were easy to grow in a variety of less-than-desirable soil conditions. They were also less perishable and more transportable than other crops. Onions also prevented thirst, which likely explains their popularity in the desert regions of Egypt and the dry plains of central China.
The Egyptians also used onions as an aid to art, medicine, and their unique mummifying practices. Moreover, the Egyptians considered onions an object of worship. To them, the onion symbolized eternity, and they demonstrated this by placing onions in their Pharaohs’ tombs. For the Egyptians, the onion’s circle-within-a-circle structure symbolized eternal life. They may also have believed that onions had magical properties useful in the afterlife.
The Greeks, in the first century A.D., used onions in a medicinal manner. Many Greek athletes in the original Olympics also believed they improved athletic performance. The athletes would eat mounds of raw onions, drink onion juice, and rub onions all over their bodies.
Later, the Romans also respected the power of onions. During their conquest of Europe, the Romans used onions because they believed onions improved vision, aided sleep, and healed toothaches and dysentery. A few centuries later, during the Middle Ages, commoners believed that onions prevented headaches and baldness. Onions were so valuable that the commoners used them as currency.
Annual vs. Perennial Onions
Although onions have a fascinating global history in mummification, healing, and currency, most Americans grow onions as vegetables for use in salads and cooking. Usually these onions are common biennial onions. However, these biennials have some drawbacks. First, growing by seed takes a long time and is not consistently successful because onions don’t always reliably produce seed. If they do produce seed, to ensure seed purity you need isolation distances up to three miles. Finally, once you harvest the onion plant, it’s gone. For all these reasons, consider some less common perennial onions. They’re easy to grow and come back year after year, and you don’t have to buy seeds every year.
Also known  as tree or walking onions, Egyptian onions are hardy perennials that can be grown in most regions of the country. They reach up to three feet tall and form clusters of small onion bulbs at the top of the stem. Eventually, the weight of the bulb clusters causes the stem to bend to the ground. The bulbs root and produce new shoots, starting the process over again. To control their somewhat haphazard propagation, simply remove some of the bulbs and plant them where you’d like the next crop of onions to grow.
Choose a sunny area with well-drained, moist soil. If you like pungent onions, add some sulfur to the soil. In late summer or early fall, plant the initial bulbs one inch deep and about a foot apart. Keep the area weeded. Onions should be ready for harvest early the next spring.
Potato onions have a milder and sweeter flavor than common onions. No one knows why they’re called potato onions, because they don’t look or taste like a potato. If it were up to me, I’d call them tulip onions, because they grow like tulips by multiplying bulbs. Although no one (except me) calls them tulip onions, other common names include ground onions or hill onions. Whatever you call them, when you plant a bulb, it eventually divides into several new bulbs. Depending on the type, the number of new bulbs varies from one to more than ten, and the size ranges from small to three inches in diameter. Typically, the larger bulbs are eaten and the smaller ones are used for planting. Grow potato onions like Egyptian onions.
Shallots  resemble oversized garlic cloves. Many people, including me, prefer shallots to onions in cooking due to their richer yet more subtle flavor. From a botanical perspective, however, there’s no such thing as a shallot. Most shallots are the same species as common onions. They have never been found growing in the wild, instead being the product of centuries of selective breeding with the goal of creating reliably producing cultivars. This started either in Palestine or further east over a thousand years ago. Returning soldiers from the Crusades brought them back to Europe, where they were crossbred with Welsh onions and multiplying onions to create the prototype of perennial shallots today.
In most areas of the country (Zone 5 or higher), plant shallots after autumn’s first frost, two inches deep and about six inches apart. If you live in a colder climate, plant shallots in early spring. Once the plants have matured, save some bulbs for planting and eat the rest.
Onions  have been cultivated and enjoyed for thousands of years. Over this time, cultures have perfected perennial cultivars that produce year after year with little fuss. Try some perennials today, and expand your garden and your palate.