You're standing in the produce aisle. It’s October. Or maybe November. There’s a massive bin of round, orange things labeled "Pumpkins" and right next to it, a shelf of long, tan, bell-shaped things labeled "Butternuts." You think you know the difference. One is for carving faces into, and the other is for soup. But here’s the thing—botanically, that pumpkin is a squash. Every single pumpkin you have ever seen, touched, or baked into a pie is a squash. But not every squash is a pumpkin.
Confused? Honestly, even the scientists get a little tripped up.
The difference between squash and pumpkin isn't actually a scientific one; it's a naming convention based on shape, color, and how we happen to use them in the kitchen. If you want to get technical—and we’re going to get technical—they all belong to the genus Cucurbita. This family is massive. It includes everything from the tiny, decorative gourds that look like they have warts to the 2,000-pound giants grown by competitive farmers in state fairs.
The Family Tree: It’s All Cucurbita
Think of the genus Cucurbita as a big, messy family reunion. Within this family, there are five main species that we actually eat. Most of what we call pumpkins and squash fall into three categories: Cucurbita pepo, Cucurbita moschata, and Cucurbita maxima.
Here is where it gets weird. A classic Jack-o'-lantern is a C. pepo. But so is a green zucchini. And a yellow crookneck squash. They are the exact same species. If you planted a zucchini next to a Connecticut Field pumpkin, they could theoretically cross-pollinate and create some bizarre, franken-fruit. On the other hand, the "pumpkin" puree you buy in a can is almost never C. pepo. Most commercial canned pumpkin, like the Libby’s brand, is actually made from Dickinson pumpkins, which are a strain of C. moschata. This makes them more closely related to a butternut squash than to the orange pumpkin sitting on your porch.
Botanist Harry Paris, who has spent decades studying the history and genetics of these plants, notes that the word "pumpkin" has no real taxonomic meaning. It’s a linguistic tool. We see something round and orange, we call it a pumpkin. We see something elongated or striped, we call it a squash.
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Why the Texture and Taste Change Everything
If you’ve ever tried to make a pie out of a standard carving pumpkin, you know the heartbreak of a watery, stringy mess. It’s gross. Carving pumpkins are bred for structural integrity and thin walls so you can cut through them easily. They aren't bred for flavor. They are essentially the "cardboard" of the squash world.
Winter squashes, like Kabocha or Red Kuri, have a much higher sugar content and a denser, creamier texture. They have less water. When you roast them, they caramelize. The "pumpkin" flavor we all crave—that nutty, earthy sweetness—is actually much more prominent in things we call squash.
- Butternut Squash: Smooth, sweet, and turns into a velvety puree. It’s the gold standard for soups.
- Acorn Squash: A bit more fibrous, but has a distinct peppery note that pumpkins lack.
- Hubbard Squash: These things look like blue alien eggs. They are huge and bumpy. But inside? Some of the best pie filling you'll ever find.
The Skin and the Stem: How to Tell Them Apart
You can usually tell what you’re dealing with by looking at the stem. This is a pro-tip for gardeners. Cucurbita pepo (most pumpkins and summer squash) usually have a very hard, five-sided, angled stem. It’s almost woody. Cucurbita maxima (like the giant pumpkins or Hubbards) have stems that are soft and corky. If you touch it and it feels like a wine cork, it’s likely a maxima.
Then there’s the skin. Summer squashes are harvested while they are still immature. Their skin is thin, edible, and delicate. You can eat a zucchini raw. You can’t eat a pumpkin raw unless you want to break a tooth. Winter squashes and pumpkins are harvested when they are fully mature. Their rinds have hardened into a protective shell that allows them to be stored for months in a cool cellar. That’s the "winter" part of winter squash.
Culinary Identity Crisis
Culinary tradition dictates the difference between squash and pumpkin more than biology ever will. In Australia and New Zealand, they don't really use the word "squash" the way Americans do. Almost every winter squash there is called a pumpkin. You go to a restaurant in Sydney and order roasted pumpkin, and you’re likely getting what an American would call a Jap or Kent squash.
In the U.S., we’ve boxed ourselves in. We’ve decided pumpkins are for desserts and front porches, while squash is for side dishes. This is a mistake.
Try using a roasted Hubbard squash in your next batch of muffins. Or use a sugar pie pumpkin (the small, heavy ones) in a savory Thai red curry. The lines are blurred for a reason—the plants don't care what we call them. They just want to grow.
The Canned Pumpkin Secret
Let’s talk about the grocery store again. Look at the back of a can of "100% Pure Pumpkin." If you look at the ingredients, it will say "pumpkin." But the FDA is very lenient here. Because the line between "squash" and "pumpkin" is so thin, the FDA allows companies to label several varieties of golden-fleshed sweet squash as pumpkin.
The Dickinson squash used by major brands is tan. It’s oblong. If you saw it in the field, you’d say, "Hey, look at that weirdly shaped butternut." But because it’s processed and canned, it becomes "pumpkin." This isn't a scam, really. It’s just that the industry knows "pumpkin pie" sells better than "squash pie."
Practical Steps for Your Kitchen
Stop buying the giant carving pumpkins for food. They are for art, not for eating. If you want the best flavor, look for the following:
- Seek out the "Sugar Pie" or "Pie Pumpkin" label. These are smaller, usually about the size of a bowling ball or smaller. They have a higher sugar-to-water ratio.
- Don't ignore the ugly ones. The Blue Hubbard or the warty Marina di Chioggia might look intimidating, but their flesh is incredibly rich.
- Check the weight. Pick up two squashes of the same size. The heavier one is usually better. It means it’s denser and has less hollow space inside, which usually translates to a better texture when cooked.
- Store them right. Both pumpkins and winter squash need a cool, dry place. Don't put them in the fridge! The cold actually breaks down the starches and makes them go mealy faster. A pantry or a cool garage is perfect.
Next time you're making a recipe that calls for pumpkin puree, try roasting a butternut squash instead. Cut it in half, scoop out the seeds, roast it face down at 400 degrees until it's soft, and then blend it. You’ll notice the color is deeper and the taste is more complex than the stuff from the can. You’ve been eating squash this whole time anyway; you might as well eat the good stuff.
To get the most out of your autumn harvest, start by experimenting with "sweet" squash varieties like Kabocha or Honeynut in place of traditional pumpkin in your baking. Always cure your homegrown pumpkins in the sun for 10 days before storing to harden the skin, which prevents rot and extends shelf life through the winter. For savory dishes, treat the small, dense "sugar" pumpkins exactly like you would a butternut squash—peel, cube, and roast with olive oil and sage.