Fall and winter – when most of the vegetable garden is slumbering – is a great time to get a jump on next year’s onion, scallion, and shallot crop.  Most members of the onion tribe (known botanically as Allium) are hardy perennials and biennials that tolerate winters in most areas of the U.S.  Garlic (as discussed elsewhere on this site) is one well-known and often-grown example – but winter onions and shallots are also ideal winter-growing crops for USDA Hardiness Zones 6 through 9 (in zones 4 and 5 they need winter protection).