Watermelons have that perfect taste at the peak of ripeness. Harvest watermelon patches a few days too early, and the fruit is devoid of its customary sweetness. Allow a growing watermelon to stay on the vine too long, and it turns spongy. So how do you time it right?
The Dilemma of Ripe Watermelons
Professional growers have forever attempted to charm the information out of the snaking vines when to pick watermelon. Ronald Smith from North Dakota State University explains that even just a few under-ripe watermelons can cause a grower’s entire shipment to be rejected by a buyer. It was this quandary that inspired students from the University of Delaware to rig a machine to detect watermelon ripeness by sound.
Operating on the principal that a thumped melon – if not yet quite ripe – produces something akin a “metallic” or ringing sound, ripeness was equated with a dulling of the auditory sensation. According to the students, the sweet spot to harvest watermelon is a sugar content that ranges between eight and 12 percent, which translates into sound frequencies ranging from 100 to 200 hertz.
Of course, this technology is not necessarily available to the average hobbyist growing watermelon in the backyard patch.
The Next Best Thing: Harvest Watermelon by Sight
Take a look at the spot where the watermelon rested on the ground. Ohio State University terms this the “ground spot.” In an immature melon, this spot is pale green or even white. As the growing watermelon ripens, it turns into a solid yellow.
Another visual clue is the appearance of the tendrils around the stem. While it is impossible to divine when to harvest watermelon simply by looking at its connection to the vine, the browning of nearby tendrils are clues that the fruit is ripe or at least close to it.
The Ultimate Litmus Test
How do you know when a watermelon is ready to harvest and the aforementioned tests did not yield a tasty specimen? Trial and error may be the only methods for making the ultimate decision.
Harvest a watermelon that looks and sounds ripe. Cut it open and sample it. Is it spongy? Pick watermelons that look and sound less ripe. Is it still devoid of the sweet taste? Pick another specimen with much more pronounced signs of being “done” or wait a few more days for the next test.
At the end of the day, learning when to pick watermelon is best done with a big knife and hearty appetite.