Watermelons are sweet, juicy, and the ultimate summer treat, but did you know they’re actually close cousins to pumpkins and zucchini? Because of that, people always argue about whether they’re a fruit or a vegetable. If we’re looking at the botany, though, the answer is pretty clear.
Roots in South Africa
Originally, watermelons hail from South Africa. Since they love a warm climate, they can be a bit finicky in cooler regions. If you wait until May to sow seeds directly into the garden, you might find they don’t have enough time to fully ripen before the first frost hits.
My pro tip? Start your seeds indoors in a warm spot by April at the latest. Watermelons crave nutrient-rich soil, but they don’t like to sit in a puddle. Keep the soil moderately moist, but once the fruit starts to ripen, dial back the watering. If you overwater at the end, the flavor can get washed out and lose that signature sweetness.
The Gourd Family Connection
Watermelons are part of the Cucurbitaceae (gourd) family. To get a head start on growth or a bigger harvest, many growers actually graft watermelon starts onto pumpkin rootstock. Varieties like the Figleaf Gourd are super resistant to diseases and have much stronger root systems.
Now, grafting can be a bit of a project, and for us home gardeners, it’s often hit-or-miss. The good news is that you don’t *have* to do it. There are plenty of varieties that produce great yields on their own roots—especially smaller “icebox” types like “Sugar Baby.”
If you live in a warmer area and start your seeds early, you can definitely grow full-sized watermelons. Just make sure the soil stays nice and warm. Keep the patch weed-free, or better yet, use a black landscape fabric. It helps suppress weeds and soaks up the sun to keep those roots toasty.
More Veggie Than Fruit
Since they belong to the gourd family, watermelons are technically classified as vegetables. If you want to lean into their savory side, try pickling watermelon! It’s a sweet and sour treat that really highlights their veggie heritage.
Of course, most of us treat them like fruit. They make an incredible sorbet without needing any extra sugar, and you can even turn them into juice or jam.
But honestly? Nothing beats a fresh slice right out of the garden. To tell if a watermelon is perfectly ripe, look for a dull skin (not shiny) and give it a good thump—it should have a deep, hollow sound.
