A watermelon is a nice juicy green colored large fruit. They require a lot of sun and water. They grow rapidly in the first stage. Seeds can sprout in a few days. The leaves and stem begin to grow rapidly and in just three weeks they are ready for transplantation. This rapid growth continues into the second stage when these plants reach about 6 feet. Then they begin to branch out and in 30 days show good branching. The first flowers begin to appear around 40 days. Then the fruit begin to show growth and in about 30 days reach a good size.