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Harvest, Storage & Post-Harvest TimingCuring Calendar for Root Crops
Curing is a short, deliberate step between harvest and storage. Not every root crop needs it, and the ones that do are easy to harm with guesswork.
Key points
- Cure potatoes and sweet potatoes, and check extension for other crops such as onions.
- Most other roots skip curing and go to cold, moist storage.
- Plan curing dates, location and weather before harvest.
- Follow current extension guidance for conditions rather than guessing.
What does curing do?
Curing is a short period of controlled conditions after harvest that lets skin toughen and small cuts and scrapes heal. Iowa State University Extension describes curing potatoes and sweet potatoes to heal damage and thicken skin, and notes that curing sweet potatoes also converts some starch to sugar.
A cured crop resists rot and holds moisture better in storage. Skip it where it is needed, and storage losses tend to climb.
Timing the harvest well makes curing work better. Roots dug before the skin has set are more likely to bruise and rot, and roots dug late in a wet spell can carry extra moisture into the curing space.
Which root crops need curing?
Potatoes and sweet potatoes are the main ones, and University of Wisconsin Extension lists onions along with them. Many other roots, such as carrots, beets, turnips and parsnips, are not cured. They go straight to cold, moist storage after being cleaned and trimmed.
If you are unsure about a crop, ask your extension office. Do not assume that curing helps every crop.
A quick way to sort your own crops is to make two columns, one for crops that need curing and one for crops that go directly to storage, and check each entry against an extension source before the season starts.
How do you build a curing calendar?
Work backward from harvest and forward to storage. Write the harvest date, the number of days you plan to cure, where curing will happen and when the crop moves to storage. Plan the weather too. A crop dug at the end of a wet week needs a way to dry first.
Leave margin at both ends. If curing space is also your garage or a shed, it may be needed for other uses, and a hard frost can arrive early in the fall.
- Harvest date and weather that day
- Curing location and how it is protected
- Start and end date for curing, from extension guidance
- Date the crop moves to storage
- Notes on losses at the end of the season
What conditions does curing need?
Curing needs warmth, humidity and air movement in the right balance, and the balance differs for each crop. Iowa State and other extension sources give numbers for potatoes and sweet potatoes, and commercial growers sometimes use a curing room.
Because this is a food storage topic, we do not give temperatures or times here. Please use the current guidance from your state extension service and the National Center for Home Food Preservation, and follow it exactly.
How do you handle roots before and after curing?
Handle gently before curing, since bruises and cuts are what curing is meant to heal, not create. Do not wash roots that will be cured, and keep them out of direct sun and rain.
After curing, sort carefully. Remove damaged or soft roots and use them first. Keep crops that give off ripening gases, such as apples, away from potatoes, according to Iowa State.
What goes wrong most often?
Common mistakes include digging in wet soil, curing in a spot that is too cold or too wet, curing crops that should not be cured, and moving crops to storage before curing is finished. Another is forgetting about a crop in the curing space and leaving it too long.
Write the start date on the container, and set a reminder for the end date.
If losses are high, look at the order of steps and the conditions before blaming the variety. Often the issue is the timing of harvest, the handling, or a curing space that was too wet or too cold.
What should you record each year?
Record the date of harvest, the length of curing and the storage losses at the end of the season. Over a few years you will see which approach works for your site.
Share notes with neighbors or a local grower group, and ask your extension office to review your plan if losses are high.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.