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Harvest, Storage & Post-Harvest TimingPost-Harvest Cooling Calendar
A cooling plan follows the harvest. The quicker field heat comes off a crop, the longer it keeps, and the plan should be laid out before the first pick, not after.
Key points
- Remove field heat soon after picking to extend freshness.
- Write a cooling plan for each crop before harvest starts.
- Match the method to the crop and volume: hydrocooling, forced air, ice or cooling room.
- Keep chilling sensitive crops apart from those that want cold storage.
What is field heat and why does it matter?
Produce picked on a warm day carries the heat of the field, and it keeps breathing and losing moisture quickly. The warmer it stays, the faster quality drops. Removing that heat soon after picking is one of the most effective ways to extend freshness.
University of Wisconsin Extension describes cooling as a central step for market crops, and the SARE project on precooling and curing makes the same point. A cooling calendar turns that idea into a schedule.
For example, if you pick lettuce at mid-morning on a warm day and leave the crates in the sun for an hour while you finish the row, you have lost much of the benefit of morning picking. The calendar helps by reminding you where the shade and the cooling steps are.
How do you build a cooling calendar?
List your crops in the order they come in during the season. Beside each, write when it is typically picked in the day, how it will be cooled, where it will be held and how soon it will be sold or used. Add a column for crops that need curing instead of, or before, cooling.
Then check the calendar against your harvest peaks. If three crops arrive the same week, you need enough cooling space and labor for all three, and a calendar shows that problem in advance.
- Crop and picking window
- Time of day for picking
- Cooling method
- Holding place
- Planned sale or use date
Which cooling methods work on small farms?
University of Wisconsin Extension lists hydrocooling, forced air cooling, ice, and cooling rooms. Hydrocooling uses cold water as a bath or shower and works much faster than air alone. Forced air pulls cool air through packed containers. Cooling rooms are good for holding but are slow at removing field heat.
Recirculated water needs a sanitizer to limit the spread of pathogens, according to the same source. Your state extension food safety program and the agency that oversees produce safety in your state can give current guidance.
Which crops are sensitive to chilling?
Not every crop wants to be cold. University of Wisconsin Extension notes that crops of tropical origin can suffer chill injury, with symptoms that include pitting on snap beans and cucumbers, internal browning in sweet potatoes, and water soaking in ripe tomatoes. Injury can be hidden at first and show up later.
Group crops by temperature needs in your plan, using guidance from extension rather than guesses. Keep chilling sensitive crops out of the cold storage that serves leafy greens and roots.
If you are unsure about a crop, ask your extension office before you chill it, since a wrong guess can ruin a harvest quietly.
What about crops that need curing first?
Onions, potatoes, sweet potatoes and winter squash are cured instead of cooled quickly. Curing heals skin and prepares them for storage. See our curing calendars for the thinking behind it, and follow your extension office for the conditions.
Mixing up the two is a common mistake. A cured crop that is cooled too fast, or a leafy crop that is left warm, will not keep.
What simple steps help everyone?
Pick in the cool of the morning when you can. Keep harvested produce in shade, handle it gently and move it to cooling as soon as possible. Clean containers and clean water reduce food safety risk.
Keep a thermometer where produce is held, and write down what you see. Your notes help you adjust the plan from year to year.
For a home garden, the same logic applies at smaller scale. A cooler, shaded kitchen counter or a clean cooler with ice packs set apart from the produce can help with short-term holding for crops that do not mind it, following extension advice for each crop.
What should you check about rules and preservation?
If you sell produce, ask your state department of agriculture about food safety rules and training. If you preserve what you grow, use tested procedures from the National Center for Home Food Preservation, and do not rely on cooling alone for safety. We do not give temperatures or times here.
Sources and further reading
Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.