Popular varieties of cooking onions (yellowskins) are Trapp's No. 8, Hustler, Norstar, Copra, Prince, Fortress, Hamlet and Corona. These are available all year round, thanks to modern storage methods.
Small bunching onions (also called green onions or scallions) are available in early June and run through to mid-November.
Large sweet Spanish and red onions are usually harvested from early September until the latter part of December. The most common variety is Yula.
One half cup (125 mL) of chopped onion contains 28 calories.
The onion originated in Asia; the first written record appeared in Mesopotamia (now part of Iraq) dated 2400 BC. It spread throughout the world and was for centuries regarded as a poor person's fare, eaten raw with a chunk of bread.
The onion's smell inspired the aboriginal people living near Lake Michigan to name a settlement after it -- they called it Chicago.
Onions are a member of the Lily family along with asparagus, tulips, the yucca plant and many others.