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How to Harvest and Store Potatoes

Potatoes for harvestHarvest potatoes young or mature.

Mature, full-size potatoes are called maincrop potatoes. Maincrop potatoes are often cured and stored for later use. Maincrop potatoes are ready for harvest when most of the top foliage has withered

Small, round, immature potatoes are often called “new potatoes.” New potatoes are usually eaten skin and all. New or early potatoes can be harvested for table use at any time.

When to Harvest Potatoes

  • Harvest large, mature, maincrop potatoes about 15 weeks after planting when the foliage begins to die back.
  • Harvest new potatoes when plants begin to flower and for another 2 to 3 weeks, starting about 60 to 70 days after planting.
  • It’s best to harvest potatoes on a warm, dry day after a few days of no rain or a cloudy day will do.
  • Some potato varieties bloom late or do not bloom. If you do not see flowers 65 to 75 days after planting, check near the base of the plant for developing tubers. Potato tubers form on underground stems called stolons. Potato stolons are typically 12 to 18 inches long; so developing tubers will be within that circumference of the plant.
Lift potatoes
To harvest new potatoes gently lift the plant with your hands or a garden trowel or hand multi-pronged garden fork.

How to Harvest New Potatoes

  • To harvest new potatoes gently lift the plant with your hands or a garden trowel or hand multi-pronged garden fork. As you lift the plant, the surrounding soil and mulch will fall away.
  • Take as many new potatoes as you need then set the plant back in place and firm the soil so that the plant and remaining tubers can grow on. (Do not leave the plant out of the soil for long; the sun can damage exposed roots and tubers.)
  • As an alternative, you can lift a whole plant for harvest and leave the neighboring plants undisturbed. The potatoes you leave in the ground will grow to become your main crop—your mature tuber crop, and the plant will produce new potatoes as well.
  • If the plant is growing in hills of very loose soil,  mulch or straw, you can simply ease your hand into the tuber zone and remove new potatoes.

How to Harvest Main Crop Potatoes

  • Mature or maincrop potatoes will be ready for harvest 2 to 3 weeks after plants turn yellow and die back—about 100 to 110 days after planting.
  • Vines will either die back naturally or, to spur harvest, you can break off the stems at ground level to stop growth.
  • Between the time the plant dies back and harvest, do not water potato plants. A dry period will allow skins to “set” or harden which is important for long storage.
  • Harvest mature potatoes using a spading fork. Work from the edge of the planting row or bed inwards.
  • Insert your fork 10 to 18 inches away from the plant stem. Loosen and turn the soil carefully so the potatoes you lift are not damaged.
  • Most of the crop will be on the same level in the top 4 to 6 inches of the soil. If you know how deep the tubers are growing, you can use a garden spade to lift the entire hill.
  • If the potato plant does not die back as the tubers mature, cut the plant off at soil level two weeks before you want to harvest the tubers.
  • It is easiest to dig potatoes when the soil is dry. If the weather has been rainy, wait a few days until the soil dries to begin your harvest.
Cure potatoes
Maincrop potatoes that you want to store should be allowed to “cure” for one to two weeks after harvest. Curing will allow cuts, nicks, and bruises to heal.

Drying and Curing Potatoes

  • Let harvested potatoes sit in the garden for an hour or so to dry. As the tubers and soil dry, the soil will drop away from the tubers. If the soil does not drop away, use a soft brush to remove soil from the tubers. Do not wash just harvested potatoes; washing potatoes will shorten their storage life.
  • Newly harvested potatoes do not have tough skin so handle them carefully to avoid bruising which can lead to rot.
  • Set the tubers on a screen or lattice where they can dry for an hour. If you leave them longer, set them in a dark, dry place where it is a bit humid.
  • Maincrop potatoes that you want to store should be allowed to “cure” for one to two weeks after harvest. Curing will allow cuts, nicks, and bruises to heal.
  • Potatoes with deep cuts or bruises are best used right away and not stored.
Harvested potatoes
Do not refrigerate potatoes; the air in a refrigerator is too dry for potatoes and can cause them to shrivel.

How to Store Potatoes

  • New potatoes will be most flavorful if eaten almost immediately after digging.
  • Store main crop potatoes in a dark, dry place for a week or two at 55° to 65° F with high humidity of 85 to 85 percent.
  • After two weeks, potatoes that you want to store longer for winter use should be moved to a much cooler– 35° to 40°F—dark room, basement, or root cellar with moderate humidity and ventilation.
  • For long storing—as long as eight months, choose potatoes that are firm with no soft spots. Temperatures higher than 40°F will cause tubers to sprout and shrivel.
  • Check stored potatoes often; if sprouts begin to form, knock the sprouts off with your hands.
  • Do not refrigerate potatoes; the air in a refrigerator is too dry for potatoes and can cause them to shrivel. Do not store potatoes with apples; picked apples expel ethylene gas which will cause potatoes to spoil.

Common Potato Storage Problems

  • Some potatoes can become “sweet” when stored. Potatoes in storage may convert starch to sugar which is used in the tuber “breathing” process. The breathing process of potatoes stored in a cool place slows so that the starch converted to sugar is not used in full; the unused sugar will give the potatoes a sweet taste when cooked. To avoid a sweet taste, take the potatoes out of storage several days in advance of cooking so that the extra sugar can revert to starch—a process called “reconditioning.”
  • The skins of potatoes exposed to light can turn green. Greening is caused by a toxic alkaloid called solanine. Green potatoes taste bitter. Do not eat green potatoes; solanine can cause illness. If a potato skin is green, peel or cut away the green before cooking.
  • Be advised that the leaves of potato plants are poisonous to humans and animals.

More tips: How to Grow Potatoes.

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18 Comments

  1. Any recommendations for storing potatoes if there is no basement or root cellar? They are nearly non-existent in my area, and there is no frost here. The coldest part of the year has lows in the 40s. Could I maybe keep them in a container in the fridge with a moist paper towel to increase humidity? Any other ideas?

    • The best place to store potatoes is in a cool, dark, well-ventilated place such as an extra refrigerator set a few degrees warmer than normal, an unheated entrance, a spare room, a garage. Store potatoes in the dark in a dark, perforated bag–you can also place a pan of water near the stored potatoes to increase humidity.

      • I bought potatoes from a farmers market, they looked like russetts and were thhe size of a peanut. Delicious!! I want to grow my own (they are not easy to find). I assume i would grow russetts. Any special tips to maximize the numbr per plant? About when would they be ready to harvest? How densely can I plant them?

        • You likely purchased new potatoes at the farmers market. “New potatoes” is another term for immature tubers or baby potatoes. You can return to the farmers’ market and ask the farmer which potato variety he sold you. You can grow new potatoes the same way you would grow mature, main season potatoes–you would simply harvest sooner. At any time during the growing season, you can move soil away from the roots-tubers and check on the size fo the tubers. Here is a link to a post on growing potatoes:
          https://harvesttotable.com/how_to_grow_potatoes/

    • Yes, you can store potatoes in sand or in a root cellar. The key is to avoid exposing the tubers to freezing temperatures; sand will insulate the tubers in all but the coldest of places. Store the tubers so that they do not touch–to avoid rot. Check your stored tubers every few weeks to be sure no rot is setting in.

  2. Hi I’m going to grow potatoes for the first time down here in South Carolina. Not use to this weather I’m originally from New York. With nice weather, great dark rich soil. We made raised garden bed. No problem. But to store potatoes is impossible. We have our house on a concrete slab. The garage gets hotter than an oven. What should I do?

  3. We are in Northern Arizona. We have a double wide and store our potatoes layered in sand in plastic totes under the house. We buy the bags of “play sand” at Home Depot. It can get fairly cold in the winter, even into the negatives. It’s incredible when there can be 2 feet of snow on the ground and a low of -5 F and the tubers stay fine in their sand totes under the house! Of course at 7,000 ft. elevation the weather is extreme. It is also common for the temps to swing up into the 50’s in the middle of winter, Either way this method seems to work well for us. The plastic totes are great for keeping out rodents and pests too! This method has worked well for us. Once a week we pull a grocery bag full out for eating. We store our carrots and beets this way too.

  4. i just harvested my very first potato crop, and some of the biggest ones have big splits in them. Do you know what causes this? They seem fine otherwise. They are red potatoes. I will eat the split ones right away, as I’m not confident of being able to harden them off and store them properly. I live in north central Indiana, right along the Michigan border. Thanks for any advice.

    • The split in the tuber is likely caused by uneven uptake of water; heavy rain, then a dry period, then more rain. This would cause the plant cells to expand and contract and thus the split. If heavy rains come, you can spread plastic sheeting around the plants so that some of the water runs away from the plant. If weather is hot, spread straw around the plants to keep conserve soil moisture. The soil should be evenly moist–not wet then dry then wet.

  5. hello dear
    thanks for sharing these valuable information with us
    my work in processing potato so i am wondering when the tubers are matured, how long can i leave it in the soil under temperature 8-10 c before harvest with no negative effects on dry matter content or sugars . thanks again

  6. I am about to plant potatoes for the first time. My shipment should arrive today (certified disease free). When they are harvested (I saw that they can stay in ground 3-5 months), can I keep a few of each variety to use as my “seed” for next year? Will those “seeds” last until the next spring to be replanted?

    Thanks,

    Susan

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