Store whole onions in a cool, dark, dry place in an open bowl or bag for several weeks. They need air around them to slow spoilage.
Store peeled or cut onions in sealed containers in the refrigerator. Use within 1 to 2 weeks.
Refrigerate green onions (scallions) and use within 1 to 2 weeks.
Freeze extra onions (raw or cooked) to prevent waste. Chop the onions and saute if desired. Place small amounts in freezer bags or containers and store in your freezer. You can also freeze raw onions on a tray. Transfer to a freezer bag or container and return to freezer. Use within 6 to 8 months in cooked dishes.