Watermelons grow in full Sun

Watermelons grow in full Sun and love hot, humid weather and light, moist, fertile, well-draining soil. During harvest, watermelons must be shaded from burning sunlight to minimize heating and sunburn. The dense leaves help provide that shade.
Many people just grow the melons on the ground, however trellising would improve air circulation and reduce disease problems. If growing melons on a trellis, support fruit with slings made from netting, fabric, or pantyhose. Choose a smaller-fruited variety for trellising.