Onions are vegetables. Research suggests that various types of onions have been cultivated for over 5,000 years and may be one of the earliest known crops.
Onions are a bulb crop, which includes garlic, leeks, green onions and dry-bulb onions. Bulb vegetables typically have underground segments. Because their structure leaves no trace when it degrades, science has been unable to definitively locate where onions were first grown. It has been suggested that they were first cultivated over 5,000 years ago in Asia or in part of the Middle East. Chinese and Indian records from the period include mention of onions. There are records from Egypt that mention onions dating back to 3500 B.C. Additionally, onions and other bulb vegetables are mentioned in the Bible.
Most common forms of onions fall into one of two categories:
- Long day: found in northern latitudes
- Short day: found in southern latitudes
The categories refer to the day length required for bulb formation. Onions are generally very versatile vegetables and can be eaten in many different ways, including raw, boiled, baked, fried, pickled, steamed and French fried. Onions are also used in combination with other vegetables, particularly in soups and stews. They are a strong cash crop in many states.