does anyone know how to tell when a watermelon is ripe.it is still on the vine.?

Question

i have a wild watermelon that has came up in my yard where someone has spit out a seed and it has a big watermelon on it

Answer 1

Watermelon is ripe when the tendril dries and the spot were the melon touches the ground turns from shiny and pale green or white to dull and cream or yellow.
The Maryland Cooperative Extension site states that on some watermelon varieties, the tendril can dry up... 10 days before the watermelon is ripe:
http://www.agnr.umd.edu/mce/publications/PDFs/FS455.pdf

Ripe melon has a dull appearance...Unripe melon has a shiny appearance.
http://forums2.gardenweb.com/forums/load/cornucop/msg0710205414678.html

Daniel Egel, Southwest-Purdue Agricultural Center, said a watermelon's appearance and feel are better gauges than the time-honored practice of tapping on the outer skin. "A watermelon that is ripe will be faded on the top. If the watermelon has stripes, look at the area between the stripes. This area should be a light green. Turn the watermelon over and look at the place where the fruit stood on the ground. If the watermelon is ripe, the 'belly spot' will be white or yellow. If you can see the stripes through the belly spot, it may not be ripe." A smooth rind usually indicates a good fruit. "You might try to avoid melons that are over-lumpy," Egel said. "Sometimes that may mean the rind on the inside is discolored, which is unappealing to some people."
Watermelons at the peak of ripeness are normally filled out and blunt on the ends. Melons with pointy ends may still be maturing and not as delicious, Egel said.

If you thump the watermelon listen closely when their finger flicks the fruit. "An unripe watermelon will 'ping' when thumped. An overripe watermelon will 'thud.' The one you want is somewhere in between."
http://www.purdue.edu/UNS/html4ever/000714.Egel.watermelon.html

Use a combination of the following indicators to determine when watermelons are ripe; (1) lightªgreen, and when the curled tendril near the stem begins to shrivel and dry up; (2) the surface color of the fruit turns dull; (3) the skin is rough and resists penetration by a thumbnail; and (4) the bottom of a melon where it touches the ground turns from a light green to a yellowish color. Watermelons will not continue to ripen after harvest.
http://w3.aces.uiuc.edu/NRES/extension/factsheets/vc-11/VC-11.html
Good Luck! Hope this is helpful.

Answer 2

when the little curly vein on the watermelon starts turning brown its ready. There is also the thump test.(thump the watermelon) Its a little hard to explain the thumping sound that it makes when its ready to be picked- Its kinda like a fullness sound.
most farmers like to pick the watermelons before the stem turns brown because insects will start eating on it if it lies on the grown ripe for to long.

Answer 3

My rule of thumb with waremelons is simple. Once the stem start to dry out and turn brownish it is ripe. If the stem is still solid and green and white, it may still need a bit to go. If it is, keep checking on it to make sure it is not rotting on the bottom.