Is Watermelon a Fruit or a Vegetable? Technically, It’s Both — and Here’s Why

Is watermelon a fruit or a vegetable? The honest answer: it depends on who you ask. Botanists call it a fruit — technically a berry, of all things. Gardeners grow it exactly like a vegetable. And the state of Oklahoma has officially declared it their state vegetable. All three groups have reasonable arguments. Here’s the full breakdown.

Find watermelon nutrition information here.

Botanically Speaking: It’s a Fruit — and Technically a Berry

Any botanist will tell you that watermelons are fruit. Here’s why: a fruit is any part of a plant that results from fertilization — a flower bloomed, was pollinated, and produced a seed-containing fruit. Under that strict definition, even beans and cucumbers qualify as fruits.

But it goes further. Watermelon is technically classified as a berry — and more specifically, a type of berry called a pepo. A pepo is a berry with a hard outer rind and fleshy interior. Cucumbers, pumpkins, squash, and cantaloupe are all pepos too, which means they’re all botanical fruits. Surprised? You’re not alone.

Other Garden “Vegetables” That Are Botanically Fruits

So what is a vegetable, botanically? It’s any edible part of a plant that is not involved in reproduction — think leaves (spinach, lettuce, kale), roots (carrots, beets, potatoes), and stems (celery). Watermelon doesn’t fit that definition at all.

Ask a Gardener

A backyard gardener may classify watermelon as a vegetable based on gardening techniques. Gardeners typically grow watermelon in the vegetable garden along with beans, peas, and corn. Watermelons require rich soil, plenty of water, and fertilizer — just like other garden vegetables. They’re planted in spring and harvested in late summer, the same rhythm as the rest of the veggie patch. It’s no wonder gardeners think of them as vegetables.

Taste for Yourself

Bite into a slice of ripe, juicy watermelon and you’ll most likely think “fruit.” Watermelons are 92 percent water and 8 percent sugar, so it’s no wonder they taste sweet. In the U.S., watermelons are generally eaten fresh in cubes or slices, or made into sweet desserts such as sorbets — reinforcing the fruit camp.

However, in some Asian cultures, watermelon rinds are pickled with savory spices and the flesh is used in stir-fries, where it behaves more like a vegetable. So in a sense, watermelon crosses both worlds depending on how it’s prepared.

Botanists call watermelon a fruit, and most people happily agree. But whether you classify it as a vegetable or a fruit, there’s no denying its appeal.

Frequently Asked Questions

Is watermelon a fruit?
Yes, botanically. Watermelon develops from a fertilized flower and contains seeds, which is the botanical definition of a fruit. It’s specifically classified as a pepo — a type of berry with a hard rind.

Is watermelon a vegetable?
Not botanically, but it’s commonly treated as one in the garden. Oklahoma even declared it their official state vegetable in 2007. Culinarily, it sits in a gray zone — sweet like a fruit, grown like a vegetable.

Is watermelon a berry?
Yes — by the botanical definition. A berry is a fleshy fruit with seeds embedded in the flesh, developing from a single ovary. Watermelon fits that criteria exactly, making it a berry (specifically a pepo).

What is a pepo?
A pepo is a specific type of berry with a tough outer rind and soft, seedy flesh inside. Cucumbers, pumpkins, squash, and cantaloupe are all pepos — and all technically fruits, not vegetables.

Is cucumber a fruit?
Yes, botanically. Cucumbers develop from flowers and contain seeds, making them fruits — pepos, to be precise — just like watermelon. Most people grow and eat them as vegetables, but the botany doesn’t lie.