Last Updated on September 17, 2026

How to Cure and Store Winter Squash (Butternut, Acorn, Spaghetti and More)

To cure winter squash, keep it warm and well ventilated for about a week (5 to 10 days at 80-85°F and 80-85% relative humidity), then store it at 50-60°F and 50-70% humidity. Those are the numbers from UMass Extension. Cure butternut, buttercup, kabocha and hubbard. Do not cure acorn squash (Iowa State Extension), and skip it for delicata and spaghetti squash too: MOFGA puts them in the same species as acorn, and UMass says curing can shorten that species’ storage life.

Winter squash curing and storage chart

Each cell names its source. Where two good sources disagree, both numbers are shown. The last column comes from the Johnny’s Selected Seeds curing and storage chart and counts months from harvest.

Print the chart

Why the curing numbers disagree

Curing does three jobs. UMass says it hardens the skin, speeds up wound healing and speeds the change from starch to sugar, so the squash reaches good eating quality sooner. The trouble is that every source gives a slightly different recipe. Here is what each one actually says:

So the common ground is warm, dry and airy, at about 80-85°F, for somewhere between 5 and 14 days. Four details from the sources settle the rest:

• Nights matter outdoors. UMass says field curing works only if night temperatures do not drop below 60°F. If they do, bring the squash under cover.
• A week or two of heat is fine; weeks on end is not. SDSU Extension says up to a week or two above 80°F right after harvest can raise sugar content without cutting storage life, but sustained temperatures above 80°F reduce storage life and eating quality.
• Let the squash tell you when it is done. University of Minnesota Extension says to cure until nicks and small cuts have scabbed over, and as a rule of thumb, the squash is cured once it cannot be punctured with a fingernail.
• Long keepers can skip a separate cure. If butternut, kabocha or hubbard will sit in storage for a few months before you eat it and has no wounds, UMass says it has time to turn starch into sugar in storage without the extra step. MOFGA says the same.

When to harvest winter squash

Pick it mature. UMass explains that a squash picked early uses starch from its own flesh to finish filling its seeds, which leaves poorer flesh and less starch to turn into sugar later. These are the signs the sources use:

• Hard rind. You cannot puncture it with a thumbnail (Iowa State).
• Dull skin. The glossy look fades as the fruit matures (Iowa State, Penn State).
• A dry, corky stem. Johnny’s calls this a good sign of maturity for hubbard, kabocha and buttercup. SDSU Extension calls stem corking, brown woody stripes where the stem joins the fruit, a better or at least equally good sign than the fingernail test.
• Ground spot. Acorn and delicata are ready when the spot where the fruit sits on the ground has turned dark orange (Johnny’s, UMass).
• Butternut color, plus time. Butternut turns tan two to three weeks before it is ready for best quality (SDSU). MOFGA says to leave it on the plant, if the weather stays frost-free, until about 55 days after fruit set.
• Spaghetti squash is ready when the fruit turns from ivory white to golden yellow (Iowa State Extension).
• Pie pumpkins are ready when uniformly orange (Iowa State).

Counting days helps too. Johnny’s and UMass put most squash at maturity 50 to 55 days after the fruit sets. Iowa State gives 55 to 60 days after flowering for acorn, 60 to 70 for butternut and 80 to 90 for hubbard, in warm weather; cool weather slows it down. From seed, the Plan My Garden planner uses 100 days to maturity for butternut and pumpkins and 90 days for spaghetti squash. UMass adds a warning about acorn squash: seed catalogs often list 70 to 76 days from seeding, when the real number is more like 90 to 100.

Harvest before a hard freeze

Aim to have squash in before the first fall frost. Johnny’s says to harvest before your first fall frost, and SDSU Extension says pumpkins and squash are sensitive to temperatures below 45°F. The Plan My Garden planner lists butternut, spaghetti squash and pumpkins as frost-tender.

If an early frost arrives first, the fruit may still be usable. Penn State Extension says pumpkins can survive a light frost that damages the vines, but a hard freeze (below 28°F) weakens the rind and lets bacteria in, which can shorten storage time a lot.

Cold short of freezing still counts. MOFGA notes that chilling injury builds up any time the fruit sits below 50°F, and the more hours of chill, the more storage life it can cost. Oregon State University Extension says to bring the harvest in once temperatures dip below 50°F for more than a week or rain becomes frequent.

To see when frost usually arrives where you garden, look up your frost dates by zip code on Plan My Garden.

Cut, do not pull, and keep a stem

Cut squash off the vine with pruning shears or a sharp knife. Iowa State says fruit with no stem left will not store well, and University of Minnesota Extension says a stem that detaches shortens shelf life. On length, the sources vary: Iowa State says a 1-inch stem, UC Master Gardeners 1 to 3 inches, Oregon State 2 to 4 inches, and Penn State 3 or 4 inches on a pumpkin but a 1-inch stub on other winter squash. My post on growing squash vertically gives the same basic advice for butternut: cut it with a sharp knife and leave a few inches of stem attached.

• Never carry squash by the stem. Penn State says the handle breaks off easily, and the break lets bacteria in.
• Handle gently. Cuts and bruises are entry points for rot organisms (Iowa State).
• Two exceptions on stems. UMass says butternut stems can be removed so they do not puncture other fruit, as long as the scar heals during curing. Oregon State says hubbard types store best with the stems removed completely.
• Clean with a dry cloth. Penn State says to wipe off clumps of soil and plant debris with a dry cloth before storage.

Curing setups at home

The sources describe three simple setups:

1. In the garden. On a warm, dry stretch, cut the squash and leave it in the bed for 7 to 10 days (Penn State, University of Minnesota). Keep it off wet ground, and bring it in if the temperature could drop below freezing (UC Master Gardeners).
2. On a patio or under a tree. UC Master Gardeners of Contra Costa suggest a dry spot with good air circulation where the irrigation will not wet the squash, at 80-85°F for 7 to 14 days.
3. Under cover. A greenhouse, high tunnel or barn works (UMass, Penn State). MOFGA adds that a greenhouse should not get too hot or drop below 60°F, and the squash should be protected from sun damage. For any covered space, University of Minnesota Extension says to keep outside air moving past the squash: open the doors and run fans.

Whatever the setup, spread the squash out and do not pile it while it cures (Penn State).

Storing squash and checking on it

• Temperature: 50-60°F. Below 50°F causes chilling injury, and long storage above 60°F costs weight because the squash respires faster (UMass). Iowa State narrows it to 50-55°F and Johnny’s recommends 55-60°F.
• Humidity: 50-70%. Above 70% favors rot organisms; below 50% the squash dries out and loses weight (UMass).
• Where. A cool basement can work well (SDSU). Oregon State says a garage often works well, especially with shelves to keep squash off the floor and a layer of straw underneath. Skip newspaper and paper bags, which hold too much moisture.
• One layer, air around each. Store squash in a single layer with a bit of space between each one (UC Master Gardeners). Low piles cut down on condensation (Penn State).
• Keep it away from ripening fruit. Apples and pears (Iowa State, Penn State, SDSU) and tomatoes (Penn State, SDSU) give off ethylene, which shortens the storage life of squash.
• Check once a week. Oregon State says to look over stored squash weekly and pull any that are softening or rotting so they do not affect the rest. If a spot appears on the rind, Penn State says to cut it out and cook the rest.
• A short cold snap can be undone. SDSU says squash can take brief exposure down to 35°F if it is brought back to about room temperature soon after, which helps reverse some of the chilling injury.

My squash post keeps it simple: store butternut in a cool, dry place and you can enjoy it well into winter. Porch pumpkins are the exception to long storage. University of Minnesota Extension says to bring them inside if a hard frost is forecast, and to eat them soon after a month or more outdoors, because outdoor conditions shorten shelf life.

What to eat first

Johnny’s rule of thumb is to eat the spaghetti squash and the smallest squash first. Put that together with the chart and the order looks like this:

1. Anything damaged, chilled or not fully ripe. Penn State says bruised or punctured squash should not go into storage, chilled fruit should be used right away, and semi-ripe fruit does not store well.
2. Spaghetti and acorn, best within about 2 to 2½ months of harvest (Johnny’s).
3. Delicata and pie pumpkins, edible at harvest and keeping 2 to 3 months (UMass).
4. Buttercup, kabocha and hubbard, from about a month after harvest through 4 to 5 months (Johnny’s).
5. Butternut last. Johnny’s puts it at its best from about 2 months after harvest through 6 months or more, eating the smaller varieties before the larger ones.

If squash is coming ready faster than you can eat it, Penn State says all types of winter squash freeze easily: bake it, mash or puree it, and freeze it in measured portions. Do not can pureed pumpkin or squash at home. Penn State notes there are no research-based recipes for it.

Quick questions

Do you cure acorn squash?

No. Iowa State Extension says the heat and humidity of curing lower the quality and storage life of acorn squash. Store it at 50-55°F and plan to eat it within 5 to 8 weeks.

How long does butternut squash need to cure?

About a week: 5 to 10 days at 80-85°F and 80-85% humidity (UMass), or 7 to 10 warm, dry days in the field (Penn State). For flavor, Johnny’s Selected Seeds shows butternut at its best from about 2 months after harvest.

Can you cure winter squash indoors?

Yes. Johnny’s Selected Seeds says to cure indoors for 5 to 7 days at 80-85°F with good air ventilation. University of Minnesota Extension says any covered space works if outside air keeps moving past the squash, so open the doors and run fans.

How long does winter squash last?

It depends on the type. Iowa State gives acorn about 5 to 8 weeks, butternut 2 to 3 months and hubbard 5 to 6 months when properly cured and stored. UMass gives butternut, buttercup, kabocha and hubbard 4 to 6 months at 50-60°F and 50-70% humidity, against 2 to 3 months for acorn and delicata.

Is a cold garage OK for storing winter squash?

Only while it stays at 50°F or warmer. Oregon State University Extension says a garage often works well, with the squash on shelves off the floor, but temperatures should not fall below 50°F. Penn State Extension says squash held below 50°F shows pitting on the skin and more decay.

Plan next year’s squash patch

Good storage squash starts with getting the plants in on time. Plan My Garden is free to start: enter your zip code and it finds your frost dates, draw your beds, pick butternut, spaghetti squash, pumpkins and everything else you want to grow, and it places each plant at square-foot spacing and builds a planting schedule from your frost dates. On my square foot gardening chart, squash and pumpkins each get 1 plant per 4 squares, a 2 x 2 foot block, and the chart says to train pumpkin vines outside the growing area. For bed counts, see how many pumpkin plants per square foot.

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