Store onions in a dry and dark place, at an even temperature. Store only onions that are mature and properly cured. Curing means they’ve had time in a warm dry place to set their skins. Do not try to store onions or garlic that are nicked, sliced, or bruised. Eat those first. Place onion and garlic in separate mesh bags or a clean and dry wooden bin or waxed box. Don’t wash your onions or garlic before you store them. Keep them very dry. While in storage, check and cull them often to make sure the onions and garlic are not sprouting or developing soft spots. Remove and eat any damaged bulbs.
Onions are a good source of Dietary Fiber, Vitamin B6, Folate, Potassium and Manganese, and a very good source of Vitamin C.
Information from Siskiyou Cooperative