Onion – food facts

Onions have been a part of the human diet for more than 7,000 years. Onions are most commonly grown in the states of Washington, Idaho, California, and Eastern Oregon.

Varieties: Onion can be rounded, egg-like or torpedo-shaped. All types of onions are divided in three groups based on the color: yellow, red and white onions.

Related: Garlic, chives, leeks

Harvest season in the LV: May- August

Growing Conditions: Onion grows in temperate regions, on the sandy and well drained soils.

Pollination: Pollinated by insects.

Cooking/Preparation required: Onions can be consumed raw, cooked or pickled.

Fertilizers or pesticides: With good growing conditions, no fertilizers or pesticides are needed. Onions are on EWG’s ‘Clean 15‘ list.

Nutrients: Onions are high in vitamin C, a good source of fiber, and add abundant flavor to a wide variety of food. Onions are low in sodium, fat, and cholesterol free.

Health considerations: Low in calories. Onion can be used to improve digestion, and to ensure good health of heart, eyes, and joints. Sliced onion can sooth insect bites and burns on the skin. When combined with crushed aspirin and little water, slices of onion can be also used in treatment of warts.


Nutrient content can vary greatly depending on soil conditions, with organic methods and a soil rich in organic matter generally producing the best results.

‘Dirty Dozen’ or ‘Clean Fifteen’ ratings do not necessarily apply to produce grown on local farms — you need to check with the farmer to determine if and when any fertilizers or pesticides were applied.