Japanese farmers have been growing square watermelons for about 45 years. There is a major reason behind this. The round and giant watermelons are very difficult to cut and store. In Japan, the summer season is known for gifting watermelons to each other, hence these square-shaped watermelons are easy to store and cut, also they look great if a ribbon is tied on them. If you are wondering how they do it, they just place the melons into square boxes till they reach maturity.