How to Store Potatoes and Onions

Written by Olivia Choong | Edited by Dan Hickey

Last Updated: May 2, 2024 References

Potatoes and onions both store well in similar environments—it should be fine to keep them together, right? Despite their similarities, these vegetables chemically interact with each other in a way that shortens both of their shelf lives. Thankfully, with some distance and the right conditions, it’s easy to store both foods for months at a time. To help you out, we’ve explained why potatoes and onions can’t get along in storage and put together a helpful guide to making your produce last. If you want to store and enjoy delicious potatoes or onions without fear of spoilage, keep scrolling!

This article is based on an interview with our plant andgardening specialist, Olivia Choong, owner of The Tender Gardener. Check out the full interview here.

Section 1 of 4:

Can you store potatoes and onions together?

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No—potatoes and onions should be stored far apart from each other. Onions produce ethylene gas, a plant hormone that encourages fruits and vegetables to ripen. When potatoes are exposed to ethylene in storage, they’re more likely to rot, spoil, or sprout before you use them. On the other hand, the high moisture content in potatoes can liquefy onions and make them leaky. Keep potatoes and onions in separate cabinets or opposite areas of the cellar or kitchen.^{[1]
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- Potatoes should be kept away from any high-ethylene foods, including apples, avocados, apricots, pears, bananas, peppers, and tomatoes.^{[2]
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Section 2 of 4:

Storing Potatoes

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Store whole, uncooked potatoes in a cool, dark, dry place. These conditions prolong the potatoes’ shelf life—too much sunlight will make them sprout or turn green, and they keep best in temperatures between 45 °F (7 °C) and 60 °F (16 °C).^{[3]
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Research source} Pantries, cupboards, and cellars are excellent spots to keep potatoes for long term storage. Countertops work for short term storage if the potatoes are kept away from sunlight and the room temperature is not too high.
- Keep potatoes away from stoves or appliances that drastically change in temperature, as well as sinks and excessively humid or damp rooms and basements.
- Keep whole, uncooked potatoes away from the fridge. Refrigeration converts the starch in potatoes to sugars that alter the potatoes’ flavor. It might also form acrylamide, a chemical which has been flagged as a cancer risk.
- Store cut, raw potatoes in water. They’ll last in the fridge for about 24 hours. Refrigerated cooked potatoes last about 3 or 4 days.
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Keep potatoes in a storage container or bag with good ventilation. Baskets, crates, paper bags or cardboard boxes with the tops open, or mesh bags are all good options. Avoid keeping potatoes in a sealed container that doesn’t breathe (like the plastic bag they come in) since this leads to moisture buildup and a shorter shelf life.
- If you have to keep your potatoes in an open space, put a loose covering over their container to block light that can cause sprouting.
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Check your potatoes for spoilage after 3 months. If you notice blemishes or black spots, a bad smell, or it’s soft to the touch, it’s gone bad and should be thrown away. Sprouted potatoes are still OK to eat—just peel or chop off the sprouts before cooking. When stored correctly, potatoes can last for up to 3 months or longer. Countertop potatoes with more light exposure might only last a week or two.
- Make sure any sprouts are completely removed before cooking since they can be toxic. If you’re not sure a sprouted potato is safe to eat, just toss it.
- Red potatoes don’t last as long as yellow or white potatoes, and thick-skinned potatoes like russets last longer than thin-skinned ones.^{[4]
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- Check on your potatoes every few weeks and remove ones that have gone bad. If needed, move them to a cooler, dryer, darker space.

Section 3 of 4:

Storing Onions

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Keep whole, unpeeled onions in a cool, dark, dry place. A basement, garage, pantry, or cabinet is ideal. Onions last longest in temperatures between 45 °F (7 °C) and 55 °F (13 °C), and a lack of sunlight and moisture means they’re less likely to sprout or mildew. Countertops work too as long as the onions are kept out of direct sunlight and the room temperature isn’t too hot.^{[5]
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- Keep whole, unpeeled onions out of the fridge. The lack of air circulation and cold temperature will cause the onions to accumulate moisture and mildew.
- Place onions away from bright windows, stoves, or other areas that experience big changes in temperature.
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Store whole, unpeeled onions in a breathable container. A basket, fruit bowl, mesh bag, or a paper bag or cardboard box with the top open allows plenty of air to circulate around the onions, keeping them fresher for longer. Make sure they’re loosely stacked for maximum air circulation.^{[6]
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- Onions are especially good at absorbing moisture. Keep your onion container away from sinks, humid basements, or any other source of excess moisture.
Whole onions with the peel removed last up to 2 weeks in the fridge. Just make sure the entire peel (the dry outer layer) is fully removed and the onion is sealed in an airtight container. Chopped onions last up to a week if they’re refrigerated in a sealed container, too.^{[7]
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Check your onions for signs of spoilage after 2 months. Whole, unpeeled onions can last from 2 to 8 months (depending on the variety) if they’re stored in the right conditions. Generally, strong or pungent onions (the kind that make you cry) last longer than sweet onions. Look for mold, discoloration, sprouting, soft spots, dry flesh, or a foul odor.^{[8]
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- Check your onions every few weeks and remove ones with signs of spoilage. If needed, move them to a drier, cooler space.^{[9]
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- In severe cases of rot, the entire onion will feel soft or squishy (probably from being around too much moisture).

Section 4 of 4:

Curing for Longer Storage

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Cure your homegrown potatoes and onions for a longer shelf life. Curing is the process of thickening and drying the skins of these vegetables so they last longer. Store-bought potatoes and onions are already cured, but it’s simple to do yourself. After curing, store potatoes and onions as you normally would.
- To cure potatoes, brush off any dirt (don’t use water) and let them sit for 10 days in a dark, well-ventilated place with moderate temperature and high humidity.^{[10]
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- To cure onions, leave them in the sun for a week. If you anticipate bad weather, place them in a covered location with good air circulation for 10 to 14 days.