The frequent appearance of images showing vibrant blue-fleshed watermelons online sparks curiosity about their existence. This striking color, often called the “Moon Melon,” captures the imagination. The definitive answer is that blue watermelons do not exist naturally in the species Citrullus lanatus. Understanding the fruit’s biology and the origin of the myth explains why this unique color is absent.
The Biological Reality of Watermelon Pigments
The color of a watermelon’s flesh is determined by its genetic coding, which dictates the types of plant pigments it can produce. Watermelons rely primarily on carotenoids, which are responsible for all naturally occurring flesh colors in the species. Red and pink hues come from an abundance of lycopene, the same carotenoid found in tomatoes. Varieties with yellow or orange flesh produce different carotenoids, such as beta-carotene, xanthophylls, and prolycopene.
The blue and purple colors seen in fruits like blueberries and grapes are created by a different class of compounds called anthocyanins. The watermelon genome lacks the necessary genetic pathways to synthesize anthocyanins in the fruit’s interior. While trace amounts can sometimes be found in the outer rind, they are not expressed in the pulp. This genetic limitation means that without advanced genetic modification, a truly blue watermelon is biologically impossible.
Sources of the Blue Watermelon Myth
The widespread belief in a blue watermelon, particularly the “Moon Melon,” stems largely from online hoaxes and digital manipulation. Images of the blue fruit began circulating widely on social media platforms around 2011, often claiming the fruit was a rare Japanese variety. These photographs were simply ordinary red watermelons whose color had been digitally altered.
This visual misinformation led to deceptive online seed sales. Various vendors began selling “blue watermelon seeds” to unsuspecting buyers hoping to grow the novelty fruit. Gardeners who purchased these mislabeled packets found that the seeds either failed to germinate or grew into common, red-fleshed varieties.
The True Diversity of Watermelon Colors
While blue watermelons are a fabrication, Citrullus lanatus offers a surprising palette of flesh colors beyond the familiar red. The most common color is a deep crimson or scarlet red. Varieties with less pigment appear pink.
The yellow and orange watermelons are naturally occurring variations that offer distinct flavor profiles, often described as having honey or tropical notes. Yellow-fleshed varieties, such as ‘Yellow Doll,’ contain xanthophylls and neoxanthin. Orange varieties like ‘Orange-Glo’ accumulate prolycopene, giving them a salmon-like hue. Finally, some heirloom watermelons, such as ‘Cream of Saskatchewan,’ produce very little pigment, resulting in a pale white or creamy-colored flesh.