Do Pumpkins Need to Come Inside When It Frosts?
The first cold snap of the season always brings the same worry. You look at the forecast, see a low near freezing, and wonder whether your pumpkins need to come inside. The short answer is that a light frost is usually fine, a hard freeze is not, and a little planning on cold nights goes a long way.
Frost and freeze are not the same thing
Frost is the ice that forms on surfaces on a clear, cold night. It can form even when the official temperature is above freezing. The National Weather Service explains that official temperatures are taken about five feet off the ground, so on frosty nights the reading may say 36 degrees while it is actually 32 degrees down at ground level. That is why your car windshield or the pumpkins on your bottom step can frost over on a night that never officially hit freezing.
A freeze is when the air itself drops to 32 degrees or lower. A hard freeze goes lower still and lasts longer.
What a light frost does
Colorado State University Extension says a light frost is not damaging to pumpkins. The University of Delaware Extension notes the same thing for growers: a light frost kills the vines and leaves but the pumpkins themselves stay sound. The thick rind protects the flesh inside. If you wake up to a little frost on your display, let it melt off on its own and carry on.
When cold becomes a problem
Heavier frosts and freezes are a different story. University of Delaware Extension says they will damage the fruit, and Colorado State recommends getting pumpkins out of the field before a hard freeze. University of Illinois Extension notes that leaving pumpkins in the field when temperatures fall below 27 degrees can lead to heavy losses.
A pumpkin that freezes through gets mushy once it thaws, and from there it softens and rots quickly. Cold also adds up over time. Oregon State University Extension says pumpkins can be damaged when temperatures drop below 50 degrees for long stretches, which is why stored pumpkins are kept at 50 to 55 degrees. On a porch you cannot control that, but you can avoid the worst nights.
When to expect the first freeze here
In southwest Ohio the first freeze usually arrives in late October. National Weather Service records for 1991 to 2020 put the normal first 32-degree reading around October 25 in both Dayton and Cincinnati. In about one year in ten it comes by October 12 or 13, and in nine years out of ten it has happened by early November. So it pays to start checking the overnight forecast by mid-October.
How to protect pumpkins on a cold night
If the forecast calls for a low in the upper 20s or a long stretch below freezing, a few minutes of work will help:
Cover the display with an old sheet, blanket or burlap in the evening. Fabric holds in a little ground heat. Avoid letting plastic sit directly on the pumpkins.
Move small pumpkins and gourds into the garage or a shed overnight. They have less mass and get cold fastest.
Pull pumpkins back under the porch roof and away from open steps, if you have room.
Take the cover off the next morning so the pumpkins can dry out.
Carved jack-o'-lanterns are more fragile, since the inside is open to the cold air. Bring them in on freezing nights if you can.
After a freeze
If a pumpkin did freeze, give it a day and then press on it. If it feels firm, it is likely fine. If it feels soft or looks wet and dark, pull it from the display so the rot does not spread to its neighbors.
Questions about your pumpkins?
If you have a pumpkin question we did not cover here, we would be glad to help. Call or text us at (513) 409-0005, or send a message through our contact page. We are a family-run business right here in the Springboro, Dayton and Cincinnati area, and we are always happy to talk pumpkins.