When to Harvest Onions
Harvest storage onions when most tops have naturally fallen over and the necks are beginning to dry. This is usually in summer or early fall in the United States, after bulbs have reached full size for their variety.
Do not force tops down early to speed harvest. Natural lodging shows that the plant is shifting from active leaf growth toward maturity, while bent or damaged green tops can create an entry point for decay.
Watch the necks as well as the foliage. A mature storage onion has a softening, narrowing neck and papery outer skin; bunching onions and sweet types are often best used fresh and may not cure or store as long.
Choose a dry day to lift onions. Loosen compact soil with a fork, lift bulbs carefully, and avoid cuts, bruises, and removing dry outer scales, because damage reduces storage potential.
Field-dry onions on the soil only if weather is reliably warm and dry and sun is not excessively intense. Otherwise, move them promptly to a protected, airy, shaded place, especially where rain, dew, or high humidity is likely.
Cure bulbs in a single layer or in shallow, well-ventilated crates until skins are papery and necks are completely dry, commonly two to four weeks. Good airflow matters more than heat, and bulbs should never be piled deeply while curing.
After curing, trim foliage only after the neck has dried, leaving a short neck, and trim roots if desired. Store only firm, undamaged bulbs in a cool, dry, dark, well-ventilated location, checking regularly and using any softening bulbs first.
Frequently asked questions
Can onions stay in the ground after their tops fall over?
They can remain briefly in dry weather, but lift them before prolonged rain or repeated heavy dew. Wet conditions raise the risk of rot and re-rooting.
How do I know whether an onion will store well?
Firm bulbs with dry, tight skins and fully cured necks store best. Variety also matters, since many sweet onions are intended for shorter storage.
Should I remove onion flowers?
A plant that sends up a flower stalk has bolted and usually will not store well. Harvest and use that bulb soon, because its center may be tough or hollow.
General guidance for US home gardens. Conditions vary by region and season; check with your local Cooperative Extension office for site-specific advice. Page updated Aug 4, 2026.