If you are growing a watermelon patch and you have several watermelons growing, you should also know when it is the right time to pick your fruit.
The average watermelon takes about 30 days to ripen on the vine. It could take slightly longer also. However, you should judge by looking for signs of ripening.When you look at the watermelon and you see a lot of white patches, then avoid plucking it. It will be still very raw on the inside. Gently pick it up from the ground without damaging the connecting stem and feel the weight. If it is light, then there is no water and you will need to wait longer for picking it.
Also, gently scratch a tiny bit of the external skin of the watermelon. If the color is a yellow and green or white mixed with green, then it could be ripe. The best parameter is to weigh it on your hand to check the water content.
These are some additional signs you can use to judge. Look at the tip of the fruit where it is joined to the vine. There will be a round yellow and white spot. This means that the fruit is ready to be picked. Once the spot appears, the fruit starts turning yellow which means it is over ripening. Another way to tell when watermelon is ready for picking is by looking at the shape of the watermelon. It should not be bulged on one side like a belly. Instead it should have a ball like shape.