A brief note to all my fellow gardeners - or semi-gardeners - whom I pestered with the question about when to harvest a watermelon... This is what I found. Of note, the famed sound of a ripe watermelon is NOT hollow, but dull (which makes more sense, given its increased water content).
Thanks to the Univ of New Mexico and their agricultural program:
Picking ripe watermelonsQuestion: How can I tell when my watermelons are ready to harvest? Every year I waste several, picking them before they are ready or waiting so long they are overripe. Thumping them doesn't work for me.
Answer: Choosing a ripe watermelon is a challenge. In the field or garden it is much easier than in the store because you will have more clues. The indications to look for in the garden are the drying of the "pigtail" or tendril closest to the melon on the vine. If it dries while the leaves and rest of the vine looks good, the melon should be ripe. The tendril is not available to melon hunters at the grocery store. A second clue, which is available at the grocery, is the color of the "ground spot," the place where the melon rested on the soil. If this ground spot is yellow or a cream-yellow color, the melon is ripe. If it is green or white, it probably is not ripe. The rind at the soil spot should toughen and resist denting with a fingernail when the melon is ripe. Finally, for those with an ear for music or who can easily distinguish sounds, the ripe melon will have a dull thud when thumped, while the unripe melon will have a tighter, ringing or hollow sound.
New Mexico State University Extension Guide H-216, "When to Harvest Vegetables" is available at your local county Extension office. This publication gives guidelines for determining when to harvest 40 common garden vegetables, including watermelons, cantaloupes, and pumpkins.
