The question of whether watermelons are male or female is a common piece of marketplace folklore, often linked to the fruit’s perceived sweetness or shape. Many shoppers believe that a rounder watermelon is a “female” and sweeter, while an oblong one is a “male” and more watery. This belief attempts to simplify the complex process of plant reproduction. This article will separate this myth from the botanical facts of the Citrullus lanatus plant and offer science-backed methods for selecting the best fruit.
The Gender Myth: Fact vs. Fiction
Botanically, the watermelon fruit does not possess a gender; it is a reproductive structure that develops from a flower. Once the flower is fertilized, the resulting fruit is essentially the mature, swollen ovary of the plant. Since the fruit is the vessel for seeds, it lacks the distinct sex chromosomes or physical reproductive organs that would classify it as male or female.
The notion that round watermelons are sweeter and oblong ones are less so is simply a generalization based on cultivar variation. Watermelons come in hundreds of varieties, and their final shape is determined by genetics and growing conditions, not by a gender distinction. Factors like temperature, soil nutrients, and water availability during growth have a far greater impact on the fruit’s final sugar content and form. Relying on shape to determine quality is misleading and ignores plant biology.
Watermelon Botany: Understanding Male and Female Flowers
The source of the gender myth lies in the plant’s reproductive structure, as the watermelon vine itself is not sexless. Watermelon plants are classified as monoecious, meaning they produce both separate male and female flowers on the same vine. These flowers are the parts of the plant that possess distinct sexual organs.
The male flowers, which appear first and are typically more numerous, contain only the pollen-producing stamen and are attached to the vine by a slender stem. Their purpose is to provide the pollen necessary for fertilization. Female flowers emerge later and are distinguishable by the presence of a miniature, unpollinated fruit—the ovary—located at the base of the bloom. This small, bulbous structure swells into the full-sized watermelon after successful pollination.
For a fruit to develop, pollen from the male flower must be transferred to the stigma of the female flower, a process usually carried out by bees or other insects. If a female flower is not pollinated within a brief window—often just 6 to 24 hours after opening—it will drop off the vine without forming a fruit. The resulting watermelon fruit is always the product of a female flower, but the fruit itself is a gender-neutral botanical structure called a pepo.
How to Select a Ripe Watermelon
Instead of looking for a mythical “female” fruit, shoppers should focus on physical characteristics that reliably indicate ripeness and high sugar content. One accurate indicator is the field spot, the creamy yellow patch on the underside of the melon. This spot is where the watermelon rested on the ground, and a deep, creamy yellow or orange color confirms the fruit was allowed sufficient time to ripen on the vine. A white or very pale field spot suggests the melon was harvested prematurely, resulting in less developed flavor.
A ripe watermelon should feel noticeably heavy for its size when lifted. This density is a direct result of the fruit’s high water content and the accumulation of sugars. Another useful sign is the presence of brown, web-like scarring, sometimes called “webbing,” on the rind. This webbing is thought to result from repeated bee activity during pollination, and a well-pollinated plant often correlates with a sweeter fruit.
The classic “knock test” can also provide a helpful cue. A ripe watermelon should produce a deep, hollow sound that resonates, similar to a tenor drum. A dull, flat thud, conversely, can indicate either an underripe fruit or one that is past its peak and potentially mushy inside. By combining these indicators, consumers can select a fruit with a high probability of being sweet and ready to eat.