The National Onion Association says that onions were first grown in Iran and Pakistan. Others believe that it originated in central Asia. But with several hundred onion cousins growing wild across the temperate parts of the world, it is quite likely that they have been eaten for tens of thousands of years. In addition to its flavor and nutritional attributes, many healing powers have been attributed to this vegetable throughout the centuries - the plant or plant portions have been prescribed for a variety of ills including coughs, colds, stomach ailments, cancer and heart problems. Onion, Allium cepa , is mentioned as being under cultivation in America as early as 1629, and is currently grown in all regions of the United States.
Onion is grown either as green or bunching types, or as bulbs.
Onions grown for bulbs are classified as either fresh or storage types. The fresh onions are spring and summer crops, high in water and sugar content and noted for their sweet, mild flavor. They do not store well and must be marketed relatively soon after harvest. Storage onions are available throughout the fall and winter. They are stronger in taste, usually smaller, have the traditional onion heat and store well.