Actually I read years ago about Americans doing that. They would visit the beach with a picnic lunch which included a whole watermelon. And the watermelon would be buried in the sand to keep it cool until they wanted to eat it. Makes a lot of sense, and I'm guesing the "gypsies" you refer to were doing the same thing.

BTW how do you know these people were gypsies?

My neighbours are Gitanos (Spanish gypsies) and they live their lives like anyone else!

This is one of the most absurd statements I have ever read in my whole life.

Has someone told you something like this or have you invented that?

they dig them up when they have sold the one they are cutting up forsale