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Knucklehead Pumpkins – Why do Pumpkins Have Warts?

Knucklehead pumpkins, as the name suggests, are covered with warts that are reminiscent of the knuckles on your hand.

This type of pumpkin, along with heirloom pumpkins of various colors and shapes, are all the trend right now for decorating.

Have you ever headed to to pumpkin patch to get your pumpkin to carve only to discover lots of pumpkins with warts on them? This begs the question: “Why do pumpkins have warts?”

Wagon with lots of pumpkin varieties.

Using pumpkins with warts in your pumpkin decor projects gives a new and interesting look to your fall decorating.

I love using natural elements in decorating projects for fall. What could be more natural than a pumpkin covered in warts?

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What are knucklehead pumpkins?

One could be forgiven for thinking that pumpkins covered with warts have some kind of disease or fungus. They certainly look the part! Does this condition mean that you have harvested too late, and my pumpkin will rot more quickly?

Don’t worry – your pumpkin patch doesn’t have a disease that will disfigure all the pumpkins to come. Knucklehead pumpkins have been genetically engineered to look this way!Knucklehead and heirloom pumpkins on shelves.

It can take at least 10 generations of cross-breeding to produce a knucklehead pumpkin that is sufficiently covered in warts to attract those that love this look.

Knucklehead pumpkins were first created and patented in 2008 in Holland, Michigan by the Siegers Seed Company, which has since been acquired by Stokes Seeds

This type of pumpkin has a rind that has vertical ridging and can vary in color from dark green to bright orange. It is covered in warts or bumps when the pumpkin matures.

Saved seeds from knucklehead pumpkins do not breed true to parent, unfortunately. To get this look, you will need to buy seeds that have been produced especially to grow a pumpkin with warts.

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If you enjoyed learning why pumpkins have warts, be sure to share this post with a friend. Here is a tweet to get you started:

Time to head on over to the pumpkin patch to find out why pumpkins have warts. The answer may surprise you!🎃🎃 Share on XWarty pumpkin on a black background with text reading "growing knucklehead pumpkins."

Varieties of Knucklehead pumpkin seeds

Since knucklehead pumpkins are now a popular commodity, growers keep coming up with new varieties.  If you would like to try your hand at growing them, some popular seeds are:

  • Frankenstein scarface – Bright orange with oval shape – harvest in about 100 days.
  • Warty Goblin –  hard orange shell with green bumps.
  • Marina di Chioggia – Warty blue squash
  • Galeux Eysines – blistered skin resembles peanut shells.

With the right seeds in hand, you can have a whole garden full of knucklehead pumpkins in the fall. Be sure to check out the growing tips card at the bottom of the post to grow your own warty pumpkins.

Can you eat knucklehead pumpkins?

The flesh of knucklehead pumpkins is yellow-orange, and dense with cream colored seeds.

Knucklehead pumpkins are most often used as a decorative pumpkin, but can also be used cooked. When you cook warty pumpkins, you will get a very sweet and mild flavor.

These warty pumpkins are ideally suited to roasting, baking and boiling for your recipes. Use them as side dishes for Thanksgiving, or roast and use the flesh in salads and soups.Sliced warty pumpkins.

You can also use knucklehead pumpkins in sweet recipes such as pumpkin chili, pumpkin cookies, pumpkin muffins, puddings and pumpkin cakes.

The seeds can be roasted and salted for a healthy snack.

Basically, once you get past the idea of dealing with the warts, you can use them in cooking the same as you would a normal pumpkin.

How large do knucklehead pumpkins get?

We’ve all seen those warty gourds sold at the grocery store that are popular around Thanksgiving. They are very small in size. Knucklehead pumpkins, on the other hand, can grow quite large.Knucklehead pumpkins can grow to 12-16 pounds.

These warty pumpkins range in size from small to medium and cam weigh about 12-16 pounds. Knucklehead pumpkins can be round, oval, or elongated in shape.

The harvest time is fall and early winter, depending on where you live. It takes about 100 to 110 days from planting to harvest.

Popularity of knucklehead pumpkins

Believe it or not, it is natural and not unusual for pumpkins to have bumps. Years of selective breeding changed all that.

For many years, the average pumpkin lover searched for the smoothest pumpkins they could find. The reason is that carving pumpkins is thought to be easier with this type of pumpkin.

As time passed, consumers started using pumpkins more and more in home decorating projects. They wanted the unusual! Once this trend took off, farmers started growing pumpkins with all sorts of warts and bumps.

These pumpkins, people have decided, add to the ghoulish appearance of a carved pumpkin, and knucklehead pumpkins became all the rage.

Lots of decorating project call for painting pumpkins white with gold stems. Do this to a warty pumpkin and you have a show-stopper!White warty pumpkins painted white with stems painted gold.

Bumps, warts, lumps and pronounced ridges all lend character to a pumpkin. Warts are now considered in, and the more the better!  

So now, what was once natural and normal, then changed to be thought of as unusual, is now cool again!

Natural reasons for bumpy pumpkins

What if you are sure that you are not growing pumpkins that are a specialized variety grown for their warts? In that case, the issue could be some sort of virus.

Mosaic virus can turn a smooth-skinned pumpkin in to one with bumps on it. In this case, the bumps will look as though they originate under the skin. This virus is spread by aphids and is characterized by small leaves on the plant, as well as leaves with blotches on them.Pumpkin with mosaic virus on a bale of hay.

A pumpkin affected by cucurbit warts from mosaic virus can look similar to a type that is actually bred for the warts. This is why it is important to know what seeds you planted!

Another cause of bumpy pumpkins is edema. If your growing season is cool and wet, your pumpkins may suffer from edema because they absorb too much water. This is similar to tomatoes with broken skin for the same reason.

If the pumpkins absorb excess water, the plant cells swell, get larger and burst. This forms a scar that can be dry and raised like a wart.

Pin this post about knucklehead pumpkins for later.

Would you like a reminder of these warty pumpkin facts? Just pin this image to one of your vegetable gardening boards on Pinterest so that you can easily find it later.Knucklehead pumlpkin on a post with words reading "Why does my pumpkin have warts?"

Warty pumpkins are odd and unique, but then again, everything about Halloween is odd and unique. so they fit right in!

Knucklehead pumpkins are large and ghoulish looking. Their warty orange skin gives off a spooky appearance that is perfect for Halloween. Why not try one this year?

If you would like to try your hand at growing warty pumpkins, print out the growing tips card below.

Yield: Pumpkins with warts

Growing Knucklehead Pumpkins

2 Knucklehead pumpkins on a wire reel.

Smooth pumpkins used to be all the rage, but lately, pumpkins covered in warts - known as knucklehead pumpkins seem to be the trend now.

They grow from special seeds. Read on to find out how to grow them.

Active Time 3 months 8 days 18 hours
Total Time 3 months 8 days 18 hours
Difficulty easy
Estimated Cost $10


  • Knucklehead pumpkin seeds
  • Compost or other organic matter


  • Hose or watering can


  1. Choose an area that gets full sunlight.
  2. Add organic matter or compost to the soil and till it under.
  3. Plant after all danger of frost has passed. Knucklehead pumpkin plants thrive in warm soil.
  4. Plant the seeds 1/2 - 1 inch deep.
  5. Space the seeds well. Knucklehead pumpkins can grow up to 12 inches in size and the vines need room too spread out.
  6. Plant in 12-18 inch mounds to encourage warmth.
  7. Water well and allow to drain. Soil should be damp, not saturated.
  8. Harvest in 100 - 110 days, depending on your variety.
  9. Harvest when the pumpkins look no longer naturally damp and the skin is stiff. Leave a stem when harvesting.
  10. Store in a dry location between 55 and 70 degrees F with normal humidity.

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Tuesday 30th of May 2023

I wanted to add that we didn't plant them. They are just growing where they landed.


Tuesday 30th of May 2023

I had one that dried out over the winter and spring. My kid broke it open several weeks ago and now we have tiny pumpkin starts in front of our planter bed. I wonder what they will look like since they won't have warts.

Carol Speake

Wednesday 31st of May 2023

What a fun discovery. Hitchhiker plants (also called volunteer plants) are interesting to watch to see how they form.


Tuesday 2nd of August 2022

Hello! I love your information on the knucklehead pumpkins, though have something to add on the seeds not sowing true. See, I have grown these for the past three years. But I haven't done so intentionally. I have never purchased these seeds, ever. But I do collect donated pumpkins in the fall once folks are done using them for decor and I feed them to my pigs. I get volunteers in both my pastures and in my garden because I add manure to my compost. One year I got loads of ghost pumpkins, the small round white ones, as well as these warts looking ones. I wish I could add pictures because I've got several growing in my asparagus bed right now, LOL! So, I don't think it would be a total waste of time for folks to try and grow these themselves from seed saving. They start out smooth and green with stripes, almost like a watermelon. Then they get knotty bumps all over them. Later, the skin turns orange, but the bumps remain green. It's really cool to witness the progression. I've got still other volunteers I'm trying to figure out - maybe acorn squash! It's a fun game every year.


Saturday 6th of August 2022

@Rachel, Lol same thing here. I started with porch decorations. I also live on a farm and have a manure pile. We tossed the decorations on the compost after fall decorations were done for. I have a large pumpkin patch of warty pumpkins at the moment. Exactly one pumpkin has a smooth skin on it. 99% are bumpy.

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