Watermelons are a classic summer fruit, but they do not grow underground like root vegetables. They grow directly on top of the soil. Watermelons are a type of gourd, belonging to the same botanical category as squash and cucumbers, and share a similar growth habit.
The Mechanics of Watermelon Growth
Watermelon plants are annuals belonging to the Cucurbitaceae family. These vines can spread extensively, often reaching six to eight feet in length as they crawl across the soil surface. The fruit, botanically classified as a pepo, develops directly from the female flower on the vine after successful pollination by insects.
The developing fruit rests on the ground for the entire maturation period, which typically takes 70 to 100 days from planting to harvest. Although the vine’s roots anchor the plant in the soil, the fruit is never buried; it sits exposed to the sun and air. This contact with the soil creates a distinct pale or yellowish spot on the underside of the melon, often called the “field spot” or “belly,” which is a sign of ripeness.
Why the Confusion About Growing Underground Exists
The confusion exists because many common vegetables are harvested from below the soil line. People are familiar with digging up root crops like carrots or tubers such as potatoes. They may assume the watermelon’s large, heavy size requires similar protection, especially since the fruit sits so close to the ground and is often obscured by the vine’s foliage.
This misconception is complicated by the fact that watermelons are often grown in fields with raised beds or hills to improve drainage. The fruit’s close proximity to the soil, combined with its lack of an obvious stem to lift it off the ground, leads many to incorrectly categorize it with subterranean produce. The fruit’s thick rind protects the flesh without needing an insulating layer of dirt.
Essential Requirements for Cultivation
Watermelons require a long, warm growing season, as they originated in the hot, arid climates of Africa. They need heat, with daytime temperatures ideally ranging between 70 and 85 degrees Fahrenheit for optimal growth. Full sun exposure is necessary for developing sweet, juicy flesh, requiring eight to ten hours of direct sunlight daily.
The plant thrives best in well-draining soil, such as sandy loam, which prevents the roots from becoming waterlogged. Watermelons need one to two inches of water per week, especially during the growth and flowering stages. Growers often reduce watering as the fruit approaches maturity to concentrate the sugars and improve the melon’s sweetness.