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Squash (Winter) Planting Calendar

Winter squash is a long-season crop that you plant in warm weather and harvest before it freezes. The calendar is built from days to maturity, frost dates and a curing period at the end.

When do you plant winter squash?

Clemson Extension lists spring planting for winter squash in South Carolina from April 15 to June 15 in the Piedmont and from March 20 to May 1 on the coast, with an additional late summer window of August 1 to August 31 on the coast. The page also says to plant only after the last frost has passed and the soil four inches deep is above 60 degrees.

Those dates belong to South Carolina. In a cooler state the safe window may open weeks later and close sooner, so use them as examples of how timing is expressed, not as a rule for your garden.

Planting dates differ even inside one state, as Clemson's separate Piedmont and coastal windows show. Ask your county extension office which window fits your county.

How do you count backward from frost?

Winter squash needs enough warm days to grow and fully ripen. Check the days to maturity for your variety, add the days to harvest to your planting date, and compare with your average first fall frost from the National Weather Service.

For example, if a variety needs about 100 days and your first frost usually arrives in mid October, you would want to be in the ground by early to mid June or sooner, adjusted for the actual packet days and a safety margin. Choose shorter-season varieties if the math leaves no room.

Here is a worked example of the arithmetic. If a variety lists 95 days and you plant on June 1, ripe fruit arrives around early September in an ordinary year, which leaves weeks of cushion before a first frost in mid October. This is an example only, so use your own variety days and your own frost dates.

What soil and spacing does winter squash need?

Squash likes fertile, well-drained soil in full sun. Vines run long, so give them space or train them onto a trellis if the variety allows. Spacing on the packet is your starting point.

Use a soil test to decide on lime and fertilizer, and follow your local recommendations. Nutrient management rules vary by state, so check requirements for larger plantings.

Large-fruited types need more space and more days than small ones, so check your packet before you mark rows. Trellising small-fruited varieties saves ground.

How do you know when to harvest?

Clemson describes mature winter squash as having a hard rind that resists a thumbnail and a dull, dry surface. Cut fruit from the vine with a generous stem, not by tearing, and avoid handling wet fruit.

Try to harvest before a hard freeze, since frost damage shortens storage life. If frost is forecast and fruit is still maturing, cover vines or pick mature fruit ahead of the cold.

Never carry a squash by its stem, since a broken stem opens the door to rot. Lift by the body and place fruit carefully in a crate or on a pad.

How do you cure and store winter squash?

Clemson describes curing at about 80 to 85 degrees and 75 to 80 percent humidity for around ten days, then storing at about 50 to 55 degrees with good ventilation, where fruit can last eight weeks or more. It also says to protect fruit from temperatures above 95 or below 50.

Home curing conditions are hard to match exactly, so ask your extension office what works locally. For cooked or preserved squash, rely only on tested procedures from the National Center for Home Food Preservation.

A common mistake is to harvest too early. Immature squash has a soft rind and stores poorly, so wait for the hard rind Clemson describes.

What pests and diseases should you plan for?

Squash bugs, vine borers and powdery mildew are common problems. Row cover at planting can exclude some pests, but remove it at flowering so pollinators can work.

Contact your county extension office for identification and current options. Follow labels exactly, observe pre-harvest intervals and protect pollinators by avoiding open blossoms.

What checklist keeps winter squash on schedule?

Winter squash gives you little room for error, since it needs a long season and careful finishing. A written plan helps.

Use this list:

• Find your average first fall frost and last spring frost.
• Choose varieties whose days to maturity fit with a margin.
• Plant into soil above about 60 degrees at four inches.
• Watch the forecast for early freezes and be ready to cover or harvest.
• Cure and store in conditions your extension office recommends.

Timing at a glance

Last reviewed: November 2026. Educational information, ranges only. Confirm timing with your county extension office.

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