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People use potatoes a lot, so you may be wondering how long do potatoes last. You may eat potatoes in some form every day, so you may be tempted to buy a big bag. 

Potatoes left on your kitchen counter may start to go bad in a week or so. If you store them in a cool darkened pantry, they can last several months. Store in a cool, humid area; darkness prevents potatoes from turning green & spoiling.

Old-fashioned root cellars had the right idea. Potatoes last longest in those types of situations. Ironically enough, potatoes do not do well in refrigerators. 

How long do potatoes last?

How long do potatoes last?

Potatoes can last a long time if kept in a cool, darkened place. 

They have very thin skin and are sensitive to light. 

Refrigerators cause them to turn starch into sugar, which causes some bad chemical things to happen. 

You can keep them peeled and in water for several days in your fridge. 

Even the potatoes you choose have an impact on how long they last.

People used to keep potatoes through the winter in their cellar. They had some left in the spring and used those to plant a new crop. A pantry around 50 degrees is almost as good and can keep potatoes for several months. On your kitchen counter, they will last a week or two.  

Potatoes can be frozen if they are cooked, but they do not do well with any kind of artificial cooling like a refrigerator or freezer uncooked. 

Cooked potatoes in a freezer will be good for a few months.  

Avoid letting them get wet because water makes them deteriorate faster. Another option is canning potatoes.

Find out whether potatoes are a fruit or vegetable.

Do potatoes go bad?

Do potatoes go bad?

Potatoes can go bad, but if you are careful, you can make them last several months. 

Potatoes can go bad quickly if they get wet or get too much sunshine. 

They usually go bad by rotting

They usually go bad by rotting. 

Potatoes should feel firm in your hand if they are still fresh. 

They can also rot from the inside, so you occasionally get a surprise when you cut into a potato.

One danger to look for is “greening” of the potatoes, which happens if they get too much sunlight, or get too warm. Chlorophyll builds up under the skin and creates a toxic alkaloid. This can make you sick if you eat too much.

When potatoes go bad, they usually start rotting and will taste very bad if cooked. 

They can start “greening”

They can start “greening,” and they can shrivel up over time. 

Storing them correctly is the best way to make them last as long as possible. 

It is a judgment call as to when a potato gets too soft to be used. 

If they are bad, they will be discolored when cooked and will taste bad.

How to tell if potatoes are bad?

How to tell if potatoes are bad?

There are several signs that a potato has gone bad. 

It is also possible for a potato to rot on the inside, which you cannot see until you cut the potato.  

Usually, there are some tell-tale signs though. 

Even stored correctly, they will eventually go bad. 

You can tell if a potato has gone bad by how it feels in your hand, and by the smell.

Potatoes get mushy and soft and may look shriveled when they go bad. It’s normal for them to smell earthy, but if it gets musty, they are most likely bad.  There can also be problems inside. If a potato feels soft in your hand, it is probably not any good.

When potatoes go bad, they do not taste good. 

Bad ones can even be unhealthy if you keep them until they start turning green. 

To some degree, it depends on your comfort level. 

How soft and mushy is the question to answer. 

If you have some rotten ones, keep them away from your good potatoes. 

The rot can spread fairly quickly in a pile or a basket of potatoes.

See the most common potato pests & how to get rid of them.

Do potatoes go bad when they sprout?

Do potatoes go bad when they sprout?

Potatoes are not bad yet when they sprout. 

This is just part of the growing process. 

If you throw some into the ground, they will start growing and a new plant will show up. 

You can eat potatoes that have sprouted as long as you do not eat the sprouts. 

The same test for freshness should be used whether there are sprouts or not. 

If sprouts are very small it should not be a concern, but when there are big ones, the potato may have started going bad.

Potatoes sprout naturally over time, even when stored in a cool dark place. That just means they have a little age on them, and the natural process is taking over. The real test is still how they feel in your hand. If they are still firm, they are still OK regardless of sprouts.

While potatoes with sprouts are not really a big deal, it can be a problem to eat the sprouts. 

There are chemicals in sprouts that are not good for humans to eat. 

Sprouts contain solanine and chaconne, which are toxic chemicals that can make you sick if you eat a lot of them. 

Potatoes sprout when they reach a certain age. 

It is just part of the natural life cycle of the plant.

See how to grow baby potatoes.

How long do sweet potatoes last?

How long do sweet potatoes last?

Sweet potatoes are a lot like what we call Irish potatoes, but sweet potatoes can last longer when stored properly. 

On your kitchen counter, they have about the same shelf life.

One advantage sweet potatoes have is they are not as easily damaged by handling or by water. 

Sweet potatoes can definitely go bad. 

One way to make them last longer is to cook them and freeze what you have cooked. 

It does not matter how you cook them. 

They do not do well in refrigerators or in freezers if they are raw.

Left on the counter, a sweet potato will last 2-3 weeks.  Sweet potatoes do well in a cool dry place & will last several months as long as they are kept ventilated & cool. They do not do well in refrigerators, but when cooked and frozen they can stay fresh for 6 months or longer.

Sweet potatoes can be kept in your pantry longer than Irish potatoes, but not a lot longer. 

Extend life with a loosely covered bag to allow for airflow. Sweet potatoes are good as long as they feel firm. 

They get mushy and shriveled when they are bad. 

Check out our article to learn more about the differences in a sweet potato.

How to plant sprouted potatoes?

How to plant sprouted potatoes?

Sprouts are how potatoes grow in the wild. 

If they are left in the ground, the sprouts will become plants that will produce more potatoes.  

In the old days, sometimes a potato plant would emerge from where it had grown the year before. 

Those were called “volunteers” and they would produce potatoes.

To plant your sprouts, mound soil into rows. Potatoes should be planted in loose soil and not very deep.  Cut your potatoes, leaving a sprout on each piece. Plant the sprouts. Continue to water and fertilize the plants and in a couple of months, you will have new potatoes growing.

Saving some of your potatoes until they sprout is a good way to start next year’s crop. 

We say they are about to go bad when they sprout, but in nature, that is just the potato reproducing itself. 

They will, however, go bad pretty soon after they have sprouted. 

Sprouts do not mean they are bad, but it means they are headed that way soon.

Find out exactly how deep to plant potatoes.

Greg Volente

Greg Volente holds a Naturalist Certificate from the Morton Arboretum, worked for The Nature Conservancy leading environmental education programs and doing natural areas restoration, and worked in the soil science research & testing lab at Michigan State University. Besides gardening, he's an avid wildflower enthusiast, and loves botanizing, hiking, and backpacking.