How to Store Potatoes and Onions | Keep Both Fresh Longer

One of the most common kitchen mistakes is keeping potatoes and onions side by side in the same basket. It’s convenient, but it shortens the life of both. The fix for how to store potatoes and onions comes down to four things: separation, airflow, darkness, and the right temperature. Here’s what actually works.

Why potatoes and onions need separate storage

Potatoes and onions spoil faster when kept together because each releases something the other can’t handle. Onions give off ethylene gas, which causes potatoes to sprout and soften prematurely. Potatoes release moisture, which makes onions mold and rot in turn.

The Ohio State University Extension’s Chow Line explains that keeping them apart and storing each in cool, dry, well-ventilated, dark conditions extends shelf life. They don’t just prefer those conditions—they need them to last more than a couple of weeks.

Beyond separation, both crops need darkness and airflow, but the specifics differ enough that they often belong in different rooms of your kitchen or pantry.

Storing potatoes without sprouting or shriveling

Potatoes need cool temperatures, darkness, and airflow. Light triggers them to turn green and develop solanine, which tastes bitter and can upset your stomach in quantity.

Basic potato storage rules:

• Keep them in a basket, open box, paper bag, or any breathable container.
• Don’t wash potatoes before storing—the added surface moisture invites rot.
• Keep them between 45–50°F for general pantry storage; 35–40°F works for long-term storage in a cellar or cool garage.
• Any storage spot above 40°F risks faster sprouting, so a warm kitchen cabinet is the wrong home.
• Cure freshly dug potatoes in a warm, dry, dark spot for 7–14 days so their skins toughen before storage.

Storing onions so they stay firm and dry

Onions want almost the same environment as potatoes—cool, dry, dark, and airy—but they’re more sensitive to trapped moisture and humidity.

Store whole onions unpeeled in a mesh bag, wire basket, open bin, or braided by their tops. Plastic bags are the quickest way to ruin onions because trapped moisture accelerates rot and sprouting.

Like potatoes, onions need curing after harvest before long-term storage. Let freshly pulled onions dry in a warm, ventilated area for 2–4 weeks so their necks seal and the outer skins paper up.

Where refrigeration fits in

Fridge temperatures and humidity change their texture—potatoes turn sweet and gritty, onions soften and get mealy.

There’s one exception worth knowing. White and sweet onions are more perishable than standard storage onions, and a gardening source notes they can go in the fridge if wrapped in paper towels first to wick moisture. For every other onion and every potato, a cool pantry, cellar, or cabinet beats the refrigerator.

When you’re ready to set up a storage spot, a container designed for keeping potatoes and onions fresh can make the separation rule easier to follow at home.

Common storage mistakes that shorten shelf life

Most spoilage comes down to a few repeatable errors. Onions go into plastic bags. Potatoes sit in a sunny counter bowl. Both crops land in the same cabinet or the same wire basket. A wet basement or humid garage spoils either crop fast. And potatoes exposed to light turn green within days.

One safety rule applies to both: discard any potato or onion with mold, soft spots, or rot immediately. One compromised onion can spread spoilage to every onion touching it, and a single bad potato can do the same to its neighbors.

FAQs

Can potatoes and onions be stored in the same cabinet?

No. Even in separate containers, storing them in the same enclosed cabinet concentrates onions’ ethylene gas around the potatoes, which speeds up sprouting. Keep them in different cabinets, different corners of the pantry, or different rooms entirely if you have the space.

How long do potatoes and onions last with proper storage?

Stored correctly in cool, dark, ventilated conditions, standard potatoes last 2–3 months and storage onions last 1–2 months. Warm pantry temperatures shorten both to about 2–4 weeks. Check stored produce weekly and remove anything starting to soften or sprout.

Should onions be wrapped before refrigerating?

Only sweet or white onions benefit from refrigeration, and only if wrapped in a paper towel first. The towel absorbs condensation and keeps the onion dry. Standard yellow and red storage onions should stay in a cool, dry pantry, not the fridge.