Onions and garlic lifted for storage are cured first - dried down in a warm, airy, shaded place for about two to four weeks until the neck is tight and dry and the outer scales are papery. Bulbs stored uncured, or poorly cured, rot in storage instead of keeping.
Promising · suboptimal if ignored → advise
How it works
At harvest the bulb's neck and outer scales are still moist living tissue and the neck is an open channel into the bulb, so curing in warm moving air dries the neck shut and the outer scales to a papery protective skin, removing the wet tissue that storage rots colonise and sealing the neck they enter by; an uncured bulb goes into storage with a moist open neck and soft scales, and decays.
What to do about it
After lifting, spread the bulbs in a single layer or hang them in bundles in a warm, shaded, well-ventilated place out of direct sun and rain, and leave them until the neck is dry and tight and the outer skin is papery - roughly two to four weeks for onions (a warm 75-90 F speeds it), two to three weeks for garlic. Only then trim, and keep the cured bulbs in mesh bags or shallow boxes in a cool, dry, well-ventilated spot. Handle gently throughout, as bruising also seeds storage rot.
How much it matters: No decay rate or shelf-life figure is invented. The sources give a curing window (about two to four weeks for onion, two to three for garlic) and warn that poor curing causes storage decay, without a quantified loss; the risk is highest for a bruised or uncured bulb stored straight off the ground and lowest for a well-cured one, and because curing is entirely the gardener's to do, the rule advises.
The evidence
Evidence: confirmed against 2 sources in the research-based literature.
the 2 sources
UMN Extension, 'Growing onions in home gardens', extension.umn.edu/vegetables/growing-onions (read 2026-08-21): 'Curing is essential if you plan to store your onions'; 'Keep the onions in a warm (75F - 90F), well-ventilated area for two to four weeks, until outer bulb scales are dry and the neck is tight'; 'Poor curing will result in decay during storage.'
Clemson HGIC, 'Onion, Leek, Shallot, & Garlic', hgic.clemson.edu/factsheet/onion-leek-shallot-garlic (read 2026-08-21): onion - 'Thoroughly air-dry bulbs in a shaded area before storage', 'To avoid storage diseases, be sure onions are well-cured before storing'; garlic - 'Cure in a warm, shady place with good air movement', 'Allow bulbs to dry until the neck is dry and the outer skin is papery, approximately two to three weeks', 'Bulb rot can also occur in storage from bruising and insufficient drying.'
Where this rule stops
Scoped to onion (allium_cepa, which also carries the bulb-onion and shallot cultivar groups) and garlic (allium_sativum), the two stored bulb alliums the sources document curing for. The corpus's FIRST post-harvest / storage advisory (trigger.kind always), so it surfaces on those species pages and can be cited by a harvest guide. Leek (grown fresh for its pseudostem) and bunching onion are out of scope. It gates nothing and docks no score - the app cannot know a bulb was cured.
Plants this fires on
Change history
Every change to this rule is one commit. This is what the project's version history records — the date and the reason — not a summary of it.
- cure onions and garlic before storage, or they rot (verified)
Cite this page
Milpa Gardens. "Onions and garlic lifted for storage are cured first - dried down in a warm, airy, shaded place for about two to four weeks until the neck is tight and dry and the outer scales are papery. Bulbs stored uncured, or poorly cured, rot in storage instead of keeping." Evidence grade: Promising. https://milpa.garden/rules/onions-garlic-lifted-storage-cured-first-dried/
A garden-planning corpus: every claim states its evidence grade and links its sources on the page. Cite it with the grade, and add the date you read it.