Storing Onions for Winter: Curing and Holding Onions Until Spring
Storing onions for winter works when they’re harvested on time, dried well and held cool and dry. University of Minnesota Extension says to harvest when about half the tops have fallen over, then dry the bulbs until the neck is tight.
The short answer
Pull onions when about half the tops fall over. Dry them in a warm, airy place for two to four weeks until the necks are tight and the skins rustle. Cut tops an inch above the bulb or braid them. Store them cool and dry. Maryland Extension cites 32°F and 65 to 70% humidity.
When should I harvest onions for storage?
Minnesota says to harvest once about half the tops have fallen. Onions that bolt form thick necks that are hard to dry, NC State notes. Too much nitrogen also leads to large necks, Minnesota warns. Soil feeding is covered in fertilizer and compost for growing outdoors.
How do I dry onions for storage?
| Step | Detail | Source |
|---|---|---|
| Dry | 75 to 90°F, good airflow, 2 to 4 weeks | Minnesota |
| Check | Necks tight, outer scales rustle | Minnesota, Iowa State |
| Trim | Cut tops 1 inch above the bulb, or braid | Maryland, Iowa State |
| Store | Mesh bag, wire basket or crate | Iowa State |
NC State says drying firms up the neck and outer scales, and excess humidity slows it down. Iowa State says two to three weeks is typical.
Where should I store onions?
Maryland Extension gives 32°F with 65 to 70% relative humidity, for up to six to seven months. A cool basement works too, with onions in vented bags for two months or more. Iowa State says to move onions out of an unheated garage before it drops to 32°F, and warns that storage that is too warm causes sprouting. Check them often and pull soft ones.
Which onions store longest?
Globe varieties store longer, Maryland Extension says. Iowa State notes sweet onions are mild while others are pungent, and lists storage onions apart from those for fresh eating.
Fall cleanup
Once onion beds are empty, clear and compost the tops, as composting cannabis garden waste and fall garden cleanup after cannabis harvest explain. Then clean the hoe and fork with help from the Kind Seed Co tips on cleaning and storing garden tools for winter.
Sources
- Growing onions in home gardens, University of Minnesota Extension
- Onions, University of Maryland Extension
- All about onions, Iowa State University Extension, Yard and Garden
- Bulb onions, NC State Extension
FAQ
How long should onions dry before storage?
University of Minnesota suggests two to four weeks, and Iowa State notes two to three weeks until the scales rustle.
What temperature is ideal for storing onions?
Maryland Extension cites 32°F with 65 to 70% relative humidity for up to six to seven months.
Can I braid onions for storage?
Yes. Iowa State says dry tops can be braided and hung from a rafter or ceiling.
Why are my stored onions sprouting?
Iowa State says storage that is too warm causes sprouting.
Which onions store the longest?
Maryland Extension says globe varieties store longer.
