Why Is My Pumpkin Rotting From the Bottom?
You pick up a pumpkin that looks perfect from the top, and your fingers sink into the bottom. It is one of the most common pumpkin problems we hear about. The good news is that bottom rot usually has a simple cause, and most of the time you can prevent it.
The bottom is where water sits
A pumpkin is mostly water. Ohio State University Extension notes that pumpkins and squash are about 90 percent water, so they are always one bruise or one wet spot away from breaking down. The bottom is the part of the pumpkin that touches the ground, the doormat or the porch boards, and it is the part that stays damp the longest after rain or morning dew.
A Kansas State University extension article advises avoiding damp bases and choosing a well-drained spot. Mississippi State University Extension gives the same advice. A pumpkin sitting in a puddle, on wet mulch or on a soggy mat can stay wet underneath for days, and that is where soft spots begin.
Some rot starts in the field
Not every soft bottom is your fault. University of Minnesota Extension explains that one common pumpkin disease, Phytophthora, often starts where the fruit touches the ground in the wettest parts of a field and then works its way upward. A pumpkin can look sound when it is picked and still break down later on display. The same source notes that wounds from insects let other rot fungi in.
That is one more reason to check the bottom before you buy. Turn the pumpkin over and press gently. It should feel hard all over.
Cold nights can leave soft spots too
University of Minnesota Extension also describes chilling injury. Cold nights, especially in low spots, can leave water-soaked areas or sunken patches on the skin. Those damaged areas then break down faster. Its advice is to cover outdoor displays on cool nights. For more on cold weather, see our post on whether pumpkins need to come inside when it frosts.
How to stop bottom rot before it starts
Lift each pumpkin off wet surfaces with a piece of cardboard, a slatted board or a hay bale
Swap out cardboard when it gets soggy
Leave a little space between pumpkins so air can move
Wipe pumpkins with a weak bleach solution, about 1 1/2 teaspoons of bleach per gallon of water, and let them dry before they go out
Never carry a pumpkin by the stem, since a broken stem lets moisture in
Our post on keeping a porch display dry has more ideas for lifting pumpkins and using the porch roof.
Check the bottoms once a week
Once a week, tip each pumpkin back and look underneath. A little dampness is fine. A dark, wet-looking or soft patch is not. Pull any soft pumpkin right away, because rot spreads to the pumpkins it is touching, and check the spot it was sitting on. Dry that area before you set anything new down.
If the soft spot is small and the rest of the pumpkin is still hard, you can move it to the back of the yard or the compost pile rather than leaving it in the display. A healthy whole pumpkin that stays dry underneath can last for weeks. Our post on how long porch pumpkins last explains what to expect.
The short version
Bottom rot is almost always about moisture. Keep the bottoms dry, give the display some air, cover it on cold nights, and check underneath every week. Those few habits do more to keep a porch looking good than anything else.
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.