How to Store Onions
Well-cured onions are among the easiest harvests to carry through a British winter. Choose only firm, fully ripened bulbs with papery skins and dry necks. They need drying first, then a dark, airy place where damp, frost and condensation cannot encourage mould or rot.
Best storage conditions
After curing, keep onions at 2-8 degrees C in a dark, dry, frost-free place with good air movement. Low humidity is important: a damp shed, sealed box or plastic bag causes skins to soften and mould to develop. A cool garage, porch or shed is suitable if it stays dry and does not freeze. Keep bulbs away from potatoes, which give off moisture and can shorten storage life.
How long it keeps
Properly cured, sound onions commonly keep for 4-8 months, depending on variety and storage conditions. Use any bulb that begins to soften, sprout or show mould first. Thick-necked onions and damaged bulbs are poor keepers, so cook them soon after harvest.
Storage methods
Lift onions in dry weather once the tops have bent and yellowed. Lay them in sun or under cover with plenty of airflow for 2-3 weeks, until the outer skins rustle and the necks are completely dry. Trim roots and loose foliage, or leave foliage long enough to make plaits. Store small batches in shallow trays, or hang net bags and plaits from a beam in a cool, dry, frost-free shed or garage. Do not overfill bags; air must circulate. Check every fortnight and remove any soft or rotting bulb immediately.
Preserving
Chop and freeze onions in small portions for soups, stews and sauces; they need no blanching, although they will be soft after thawing. Pickled onions are useful for small bulbs, provided a trusted recipe is followed. Onion chutney, marmalade and slow-cooked relishes also turn a glut into store-cupboard jars. Dehydrate sliced onions until brittle, then keep them in airtight containers in a cool cupboard.
Tips
Avoid storing onions beside fruit, potatoes or anything damp. Label varieties if you grow several, as mild or sweet types often keep less well than traditional storage sorts. Never put wet bulbs away after rain. One rotten onion can quickly spoil its neighbours, so regular checks are worthwhile.
Storing Onions: frequently asked questions
How do I store onions?
Lift onions in dry weather once the tops have bent and yellowed.
How long does onions keep in storage?
Properly cured, sound onions commonly keep for 4-8 months, depending on variety and storage conditions.
What are the best conditions for storing onions?
After curing, keep onions at 2-8 degrees C in a dark, dry, frost-free place with good air movement.
Store only sound, dry produce and check regularly. For bottling and preserving, follow a trusted recipe. Page updated 19 Sep 2026.