Post-Harvest Handling & Storage Guidelines for Classic Storage Crops

4 Basic Temperature/Humidity Combinations for Classic Storage Crops

Storage crops are harvested and then held in a partly or fully controlled environment so they can be eaten or sold over the following weeks and months. Most come in from the field in fall and are kept through winter under one of four basic combinations of temperature and humidity:

Cold and dry
Cold and moist
Cool and dry
Cool and moist

The group includes most, but not all, root and tuber vegetables; hard-skinned cucurbits such as winter squash and pumpkins; and certain head crops, usually brassicas like cabbage.

Grains, dry beans and dried flowers also count as storage crops, though they are handled in other ways.

The best storage conditions and how long a crop will keep depend on the crop and type, and sometimes on the variety, the growing conditions and when it was harvested. This quick guide to handling and storing the classic storage crops starts with some practical points, followed by basic guidance for each crop.

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Practical Considerations

Many growers avoid storing crops because they assume conditions must be perfect for produce to last. That isn't really true. Keep the following in mind.

We list ideal storage temperatures, but most crops still keep reasonably well when conditions fall short of ideal.
Crops that prefer 32°F (0°C) will usually still keep for a shorter but useful period, often a couple of months for some crops, at temperatures up to about 50°F (10°C), as long as humidity stays high (onions are the exception, preferring drier air).
In many climates a garage, basement or mudroom offers these conditions, and older houses sometimes have a root cellar, or the remains of one, already in place.
Get as near as you can to the target temperature and humidity, prepare the crop correctly, and it will last a good while.
We suggest perforated bags for carrots, beets, turnips, leeks, celeriac and all brassicas. Partly enclosing produce helps hold humidity, but the bags need enough openings for air exchange so the crop doesn't rot.
Also remember to eat what you store, and start early. Some people try so hard to make stored produce last that they hold back from using it, which backfires if spoilage sets in. Even in perfect conditions, crops can break down without warning. It is better to finish your last vegetables in late winter than to throw out half of them in spring.

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Root Crops & Tubers

Root crops and tubers are what most people picture as storage crops, so we start with them, then cover alliums, brassicas and cucurbits, with some of our favorite and best-performing varieties for each.

Beets & Carrots • Tips for Post-Harvest Handling

Harvest in dry weather if possible, when soil falls away from the roots easily.
With beets and carrots, cut the tops off close to the root, leaving about ¼" of stem. Leaving more invites rot, while cutting flush makes the root dry out faster.
Whether you wash roots before storing depends on your setup, when washing fits your workflow, how your wash-pack area is arranged and what your buyers prefer.
Soil biology matters too. Wetting roots can promote rot, and washing removes not only disease organisms but also helpful microbes in the thin soil layer on the root that can help hold decay back.
Rather than washing, you can gently knock off clumps of soil, using nothing rough that could scrape the skin.
Then wash the roots as you take them out of storage over the winter.
If you do wash first, let roots air-dry before they go into storage.

Beets typically keep 3–5 months in cold, humid storage, and some keep longer. Shown above: 'Merlin' Organic Beet

Beets—Cold & Moist

Dig before the first hard freeze, when roots are roughly 1¼–3" across.
Cut the tops (leaves and stems) back to ¼" long.
Remove the taproot with a sharp knife before storing.
Store in perforated plastic bags or in closed containers of damp sand.
Beets of every variety keep about 3–5 months at 32°F (0°C) with 90–100% relative humidity.

Carrots—Cold & Moist

'Bolero' is a favorite late-season carrot, ideal for harvest in late fall and winter, and it stays flavorful, sweet and crisp through long storage.

Harvest carrots for storage ahead of the first hard freeze.
Cut tops back to ¼" long. Store in perforated bags or in closed containers of damp sand.
Ethylene from some fruits, such as apples, harms carrots, so store them apart.
Hold at 32°F (0°C) and 90–100% relative humidity.

Tip: 'Bolero' is an excellent choice for late-fall harvest and keeps for many months in the conditions above.

Celeriac (Celery Root)—Cold & Moist

Harvest celeriac before the first hard freeze.
Cut tops back to about ¼".
Store with the soil and roots left on.
Keep in perforated bags or in a closed container of damp sand.
Clean the roots before sale.

Tip: 'Brilliant' is a great storage celeriac, with big, round, firm roots that keep almost as long as carrots in the same conditions.

Kohlrabi—Cold & Moist

'Kossak' kohlrabi stores well for a few months.

Harvest storage kohlrabi while the root is still round and before it starts to lengthen.
Strip off the leaves and stems before storage.
Store in perforated bags.
Hold at 32°F (0°C) and 90–100% relative humidity.

Tip: 'Kossak' keeps its firm white flesh sweet, tasty and tender through 2–3 months or more of storage.

Parsnips—Cold & Moist

Mow off the tops, then loosen with a broadfork or undercutter, or use a root harvester.
Parsnips need a long season, and cold weather sweetens them. Dig in fall or leave them in the ground over winter.
For spring harvest, dig before new tops start growing for the best roots.
Store them like carrots, unwashed or washed, in perforated bags or bins at 32°F (0°C) and about 95% or higher relative humidity, but handle them gently since they bruise more easily.

Potatoes—Cold & Moist

Pinto Gold Organic Potato: Good Storage Potential

'Pinto Gold' potatoes store very well.

Plants are mature once the foliage dies back on its own. Late varieties may need the vines mowed to push them to maturity before frost.
Leave tubers in the soil at least 2 weeks after the vines die so the skins can set. Don't let tubers freeze, or they turn watery and unusable.
Dig and let the skins dry in the air for a day if no rain is forecast.
Don't wash storage potatoes or put them away wet.
Store in mesh bags, crates or ventilated boxes.
Keep in a dark cooler at about 38–40°F (3–4°C) and around 95% relative humidity.
Sound tubers can keep 5 months or longer in the right conditions.

Tip: Good storage varieties include 'Yukon Gold', 'Kennebec', 'Elba', and 'Pinto Gold'. For details, see our Potato Varieties Comparison Chart.

Rutabaga—Cold & Moist

Harvest rutabaga once roots reach the size you want, ideally after a few frosts.
Cut off the tops.
Hold at 32°F (0°C) and 90–100% relative humidity.
Clean roots can be waxed before sale to slow drying, but waxing is optional.

Tip: 'Helenor' and 'Laurentian' keep about 4–6 months in these conditions.

Sweet Potatoes—Cool & Moderately Moist

Harvested sweet potatoes ready for curing

Freshly dug sweet potatoes waiting to be cured.

Sweet potatoes can be dug once they are the size you want, but always before frost, which damages vines and roots.
Cut the vines at ground level and lift the roots with a fork.
Handle very gently to protect the skin, and don't wash them.
Cure in a warm (about 85°F / 29°C), dark, well-ventilated spot at 85–90% relative humidity for 5–7 days.
Then store in crates or ventilated boxes in the dark at about 55–60°F (13–16°C) and 85–90% relative humidity. Keep them above 50°F (10°C); colder temperatures cause chilling injury.
After curing, wait a few weeks before selling or eating them; sweetness and eating quality improve.
Well-handled roots can store for 4–7 months.

Turnips—Cold & Moist

'Purple Top White Globe' turnips keep about 4–5 months in cold, humid storage.

Harvest turnips when roots reach the size you want.
A light frost can improve the flavor.
Waxing is possible but optional.
Hold at 32°F (0°C) and 90–100% relative humidity.

Tip: 'Purple Top White Globe' keeps about 4–5 months in these conditions.

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Alliums

Garlic—Cool & Dry

Garlic hung up to cure. Garlic keeps best in dry storage.

Harvest in summer once the lowest leaves start to yellow and several lower leaves have browned. Depending on your climate and the season, that may be anywhere from early to late summer. Don't leave bulbs in the ground too long or the cloves will split apart and rot.
Lift with a spading fork, taking care not to bruise bulbs, and brush off loose soil before curing.
Curing (partially drying the bulbs) after harvest is essential to prevent rot in storage. Choose a warm, shaded, airy spot such as a barn, garage or attic. Keep air moving gently, but don't aim a fan straight at the bulbs. Protect them from strong heat and direct late-summer sun, for example in a greenhouse. Hang in bunches or lay in one layer on screens or racks. Cure until the necks are dry and the wrappers are papery, usually about 2–3 weeks, longer in cool or humid weather.
For storage, braid softneck garlic or tie hardneck heads in bunches and hang them, or cut off the stems and keep bulbs in mesh bags, crates or open containers.
Keep garlic dry and well ventilated. For long-term storage, extension guidance recommends about 32°F (0°C) at 60–70% relative humidity; for home storage, a cool, dry room around 55–65°F (13–18°C) also works. Avoid holding garlic at about 40–50°F (4–10°C), including most home refrigerators, since that range encourages sprouting.

Leeks—Cold & Moist

Leeks: Bandit and Lexton leeks store well in the field.

'Bandit' can stand in the field well into winter.

Leek varieties differ in how long they take to mature (days to maturity, or DTM), and that time is closely linked to how much cold they can take:
- Early leeks grow quickly and are harvested from late summer into early fall, but handle cold poorly.
- Midseason leeks mature in fall and are fairly cold-hardy.
- Late leeks mature from late fall into early winter and are the hardiest. They can stay in the field and be harvested as needed, and in mild areas may survive winter with some protection.
Harvest early (summer) leeks first, then midseason (fall) leeks, then late (winter) leeks.
Loosen plants with a fork to lift them.
Either method below keeps leeks for several weeks:

Trim tops and roots and peel off the outer leaves. Box and store near freezing (32°F / 0°C) at about 95% relative humidity.
Cut back the tops and remove any dead leaves. Shorten roots but leave an inch or two. In a root cellar, stand plants upright in a container with roots set in moist soil, sand or peat. A little light keeps the tops green. Finish trimming roots and outer leaves before sale or use.

Tip: 'Bandit' can stand in the field well into winter. For details, see our Leek Harvesting Program.

Onions—Cold & Dry

onions curing on tables in shaded greenhouse

Onions curing under shade cloth in a greenhouse.

Once necks soften and roughly half the tops have fallen over, pull the onions and cure them in the field for 2–7 days, depending on the weather. If rain is likely, cure in a warm (about 80°F / 27°C), dry spot such as a barn or shaded greenhouse. Too much sun can scald the bulbs.
Move them to shelter, such as a barn or shaded greenhouse, to finish drying with good airflow, adding fans if needed. Keeping onions at least a foot from walls also helps air move. Skins should be dry and necks dry and tight, not slipping when pinched.
Cut tops to about 1" above the bulb and trim the roots.
Store in mesh bags, crates or ventilated boxes, since poor airflow shortens storage life. Keep in a dark cooler near freezing (32°F / 0°C) at 65–70% relative humidity.
Don't store with potatoes or other moist root crops.
Pungent storage onions usually keep 4–6 months or more. Short-day onions and most sweet or mild onions contain much more water and keep only a few weeks; they are often labeled mild or sweet because they taste noticeably gentler than storage types.
Check onions regularly in storage and remove any that are soft or rotting.

Tip: Lots of onion varieties store, but some keep much longer than others. See our Full-Size Onion Comparison Chart.

Shallots—Cold & Dry

When necks soften and tops fall over, pull and cure in the sun for at least 2–7 days depending on weather, then move under cover to finish drying.
Once dry, cut off tops and roots and store in onion bags or shallow boxes near freezing (32°F / 0°C) at 65–70% relative humidity.
Shallots can keep for up to about 6 months.

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Brassicas

Brussels Sprouts—Cold & Moist

'Divino' Brussels sprouts can be picked after frost.

Pick sprouts at roughly 1" across.
Store cut sprouts in perforated bags at 32°F (0°C) and 90–100% relative humidity.
You can also cut whole stalks, which keep for several weeks.

Tip: 'Divino' is quite cold-hardy and can stay in the field for harvest after frost. For details, see our Brussels Sprouts Harvesting Program.

Cabbage—Cold & Moist

'Promise' stores exceptionally well, often lasting into spring from a late-fall harvest.

Cut when heads are tight and firm.
Leave a few outer wrapper leaves on and store at 32°F (0°C) and 90–100% relative humidity.
Clean up heads before sale.

Tip: 'Promise' can last into spring from a late-fall harvest in these conditions.

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Cucurbits

Specialty/Ornamental Pumpkins—Cool & Dry

'Musque de Provence': a classic long-keeping pumpkin.

Ornamental pumpkins are ready once their color has fully developed.
Mature fruit can stay in the field, but too much sun at this stage dulls the color of the fruit and stem (handle).
Fruit can handle a light frost or two before harvest.
Cut handles close to the vine. Don't lift pumpkins by the handle, and avoid nicking the skin.
Cure in the sun in the field for 5–7 days, or indoors at 80–85°F (27–29°C) with good ventilation for 5–7 days.
Bring white varieties out of direct sun once the vines start to die back, and cure them indoors away from sunlight so they don't yellow.
Some growers wipe or dip fruit in a dilute bleach solution after curing.
Store at 50–60°F (10–15°C), 50–70% relative humidity, with good airflow.

Tip: 'Long Island Cheese,' 'Musque de Provence,' and 'Baby Bear' are all known for keeping well and eating well. In the conditions above they can last several months after frost.

Winter Squash & Pie Pumpkins—Cool & Dry

Winter squash curing.

Winter squash and pie pumpkins usually mature about 50–55 days after fruit set; harvest before a hard frost.
Cut fruit from the vine and handle gently.
Cure in the sun in the field for 5–7 days, or indoors at 80–85°F (27–29°C) with good airflow for 5–7 days.
Store at 50–60°F (10–15°C) with 50–70% relative humidity and good airflow. Repeated temperatures under 50°F (10°C) can cause chilling injury.
How long each type stores, and when it tastes best, varies.

Tip: As a general rule, sell or eat small-fruited types first, like acorn, delicata, mini kabocha and mini butternut. See our handy Winter Squash Curing and Storage Chart for typical curing times and storage life. To learn what affects the eating quality of winter squash and pumpkins, read our article on Eating Quality in Winter Squash.

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Learn More

Remember, check produce carefully and remove anything showing disease or rot before it goes into storage, and keep checking and culling during storage, because decay spreads quickly. Enjoy your harvest!

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Post-Harvest Handling & Storage Guidelines for Classic Storage Crops

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4 Basic Temperature/Humidity Combinations for Classic Storage Crops

Practical Considerations

Root Crops & Tubers