Fertilizer recommendations based on soil tests are given below. See Soil Management for organic sources of these materials. Planting Watermelons are planted on 80-inch wide beds with 2 to 4 feet between plants. Seeds are drilled 1.5 inches deep for large and .75 to 1 inch deep, for small-seeded cultivars. In the absence of intensive management practices such as container-grown transplants, drip irrigation and black plastic, a maximum density of 900 to 1000 plants per acre is generally recommended.
Seedless watermelons are less hardy and grow more slowly than conventional cultivars.
They are generally transplanted because of the high seed cost. With both types of watermelons, Florida growers are being urged to plant more deeply up to the seed leaves rather than the top of the root ball in order to increase vigor. Deeper planting seems to protect seedlings from wind damage and promotes high early yields. Water Requirements and Mulching Without adequate water, starting early in the fruit development stage and continuing through harvest, the incidence of misshapen fruit and fruit with blossom end rot increases. Pollination One to two hives per acre are recommended to improve quality and size of watermelon fruit.