Post-Harvest Handling & Storage Guidelines for Classic Storage Crops

4 Basic Temperature/Humidity Combinations for Classic Storage Crops

Classic storage crops are products that are held post-harvest in a semi-controlled or controlled environment, for use/sale over the ensuing weeks and months. Most are harvested in the fall, then held for winter storage under 4 main combinations of low-temperature/humidity:

• Cold & Dry
• Cold & Moist
• Cool & Dry
• Cool & Moist

Crops that fit into the classic storage-crop category include most—though not all—root vegetables and tuberous vegetables; hard-shell cucurbits, that is, winter squashes and pumpkins; and some head crops, typically those that are brassicaceous, such as cabbages.

Grains, beans, and dried flowers, too, can be considered types of storage crops, though they are handled differently.

Optimal storage conditions as well as holding times vary by crop and type—and in some cases by variety, environmental conditions, and season or timing of harvest. Here's a quick guide to post-harvest handling and storage of classic storage crops. First we cover some practical considerations, then provide basic, crop-by-crop specifics.

Practical Considerations

A lot of people shy away from storage because they think they have to maintain perfect conditions to keep the produce in storage as long as possible, but that's not necessarily the case. Here are some guidelines to keep in mind.

• We give the ideal temperature ranges for storage, but you can get a decent storage life out of most crops even if conditions are not perfect.
• For all the crops that should be stored at 32°F (0°C), you can expect to get half the storage life (2–3 months for some things may be quite reasonable) by storing them in temps up to 50°F (10°C), provided there is high humidity (except for onions, which like it a little drier).
• A lot of people live in climates where they have this type of situation in their garage, basement, or mud room. Older structures and foundations may even have an existing root cellar or the potential makings (or ruins) of one.
• If you can get as close as possible to the target temperature and humidity, and if the crop is prepared properly, it will keep for a good while.
• We also recommend storing carrots, beets, turnips, leeks, celeriac, and all brassicas in perforated bags. Most crops will be able to maintain high humidity better if they are somewhat enclosed, but the bags must breathe well enough for air exchange to prevent decay.
• Another thing to try to keep in mind is to eat what you store, and don't wait! Some people try to stretch the life of their storage crops as long as possible, and in doing so can be reluctant to eat them early on. This can really backfire if things start to rot for whatever reason. Even under ideal conditions, crops can go bad at any time. You are better off having enjoyed the last of your veggies in February than you are throwing out half your stash in April.

Root Crops & Tubers

Because most people think of root crops and tubers first when they think of storage crops, we provide information for them first, then alliums, brassicas, and curcurbits, including a few examples of our recommended favorites and top-performing varieties.

Beets can be kept for 3–5 months under cool, moist conditions; some can be stored up to 6 months. Shown above: 'Merlin' Organic Beet

Beets—Cold & Moist

• Harvest before the first hard freeze, at about 1¼–3" in diameter.
• Trim tops (stems and leaves) to ¼" in length.
• The taproot should be cut off with a sharp knife prior to storage.
• To store, pack in perforated plastic bags or in sealed containers filled with damp sand.
• Beets of all varieties will keep for 3–5 months when stored at 32°F (0°C) and 90–100% humidity.

Carrots—Cold & Moist

'Bolero' is a late-season favorite: perfect for late fall and winter harvest, maintaining good flavor, sweetness, and crunch with long-term storage.

• Harvest carrots for storage before the first hard freeze.
• Trim tops to ¼" length. To store, place in perforated bags, or pack in damp sand in sealed containers.
• Carrots are sensitive to ethylene gas emitted by certain fruits (such as apples), so be sure to keep them separate.
• Store at 32°F (0°C) and 90–100% humidity.

Tip: 'Bolero' is the best variety for harvesting in late fall, and will hold for up to 6 months under the above-noted conditions.

Celeriac (Celery Root)—Cold & Moist

'Brilliant' celeriac: pure celery flavor with excellent storage potential.

• Harvest celeriac prior to the first hard freeze.
• Trim tops to ¼" in length.
• Store harvested celeriac with soil and roots intact.
• Can be placed in perforated bags or packed in damp sand in a sealed container for storage.
• Clean before selling.

Tip: 'Brilliant' is an excellent celery root choice for storing, with large, round, solid roots that will hold nearly as long as a carrot under the same conditions.

Kohlrabi—Cold & Moist

'Kossak' kohlrabi can be stored for up to 4 months.

• Harvest storage kohlrabi while the tap root is still round, before it begins to elongate.
• Remove leaf stems and tops prior to storing.
• Can be placed in peforated bags for storage.
• Store at 32°F (0°C) and 90–100% humidity.

Tip: 'Kossak' is a variety that maintains its dense white flesh—still sweet, delicious, and tender—with storage for 2–4 months.

Parsnips—Cold & Moist

'Albion' is a parsnip variety well suited to fall harvesting.

• Mow tops then broadfork or undermine, or use root crop harvester.
• Parsnips require a full season of growth, and their sweet flavor is brought on by cold weather. Harvest in the fall or leave in the ground through the winter.
• When harvesting in early spring, dig before the tops begin to re-grow for the highest quality roots.
• Storage conditions are the same as carrots—hold unwashed (or washed) in perforated bags or bins at 32°F (0°C) and 95% relative humidity—but they should be handled with more care as they bruise more easily.

Potatoes—Cold & Moist

'Pinto Gold' potatoes have excellent storage potential.

• Plants are mature when foliage naturally dies back. Late-maturing varieties may need to be flail-mowed to encourage maturity prior to frost.
• Tubers should remain in the ground for at least 2 weeks after foliage has died back to allow for skin set. Do not allow tubers to freeze, as they will become watery and unusable.
• Dig tubers and allow skins to air dry for a day if rainy weather is not expected.
• Do not wash tubers for storage or put wet tubers directly into storage.
• Place in mesh bags, crates, or vented boxes.
• Store in a dark cooler at 40°F (4.4°C) and 95% relative humidity.
• Healthy tubers can store for 5 months or more under the proper conditions.

Tip: Varieties with excellent storage potential include 'Yukon Gold', 'Kennebec', 'Elba', and 'Pinto Gold'. For more information, see our Potato Varieties Comparison Chart.

Rutabaga—Cold & Moist

Shown here: Sweet, mild 'Laurentian' rutabaga

• Harvest rutabaga when roots reach the desired size, preferably after a couple of good frosts.
• Remove tops.
• Store at 32°F (0°C) and 90–100% humidity.
• Clean roots may be waxed prior to delivery at market to prevent drying, but this step is not necessary.

Tip: 'Helenor' and 'Laurentian' will keep for 4–6 months under the conditions noted above.

Sweet Potatoes—Cool & Moderately Moist

'Mahon Yam™'—cured properly, this organic sweet potato has excellent storage potential.

• Sweet potatoes can be dug whenever they reach the desired size, but should always be harvested prior to frost as the plants and roots will be damaged otherwise.
• Clip vines at soil surface and dig tubers with fork.
• Handle tubers very carefully to avoid damaging skin; do not wash.
• Cure tubers in a warm (85°F / 29°C), dark place with good ventilation and 85% relative humidity for 5–7 days.
• Place tubers in crates or vented boxes and store in dark at 60°F (16°C) and 85% relative humidity. Do not allow the storage temperature to drop below 50°F (10°C), as this will chill and injure the tubers.
• Once cured, store the tubers for 3–4 weeks before selling and/or consuming for better sugar content and eating quality.
• Properly handled tubers can be stored for 7 months or more.

Turnips—Cold & Moist

'Purple Top White Globe' turnip can be held for up to 4–5 months under cold, moist conditions.

• Harvest turnips when the roots have reached the desired size.
• A light frost can enhance flavor.
• May be waxed, but this is not necessary.
• Store at 32°F (0°C) and 90–100% humidity.

Tip: 'Purple Top White Globe' can be kept up to 4–5 months under the above conditions.