Do I Plant the Black or White Watermelon Seeds?

Genetics

• Black watermelon seeds are the mature seeds of the fruit, while the white seeds are the immature form. Not all melons carry both types of seed. Seedless or triploid watermelons do not produce fully developed seeds -- the black seeds -- and the white seeds they create would be sterile due to their genetics, according to the University of Illinois Extension. The seeds contain three sets of chromosomes, too many to divide evenly for proper reproduction, explains the Purdue University Department of Botany and Plant Pathology.

White Seeds

• The white seeds in watermelon are edible. The seed coats remain undeveloped, and the seeds are "small, soft, white, tasteless," according to the University of Illinois Extension. The extension notes that seedless melons are favorable because their energy goes into producing sweeter flesh, rather than seeds for the next generation of plants. These melons are also easier to prepare and eat because there is no need to remove the mature seeds.

Planting

• Plant the black watermelon seeds. Watermelons are warm-season, tender plants. They thrive in temperatures of 70 to 80 degrees Fahrenheit. Because of the need for a long growing season and high temperatures for good performance, transplants are often used, rather than direct seeding. Black plastic mulch can warm the soil to provide a longer growing season and provide a barrier to weeds in your watermelon patch.

  Place your seeds at a depth of 1 inch. If planting in hills, place two seeds per hill in hills spaced 4 to 5 feet apart. When planting in rows, leave 5 to 6 feet between plants and 6 to 8 feet of space between rows.

Growing Seedless Watermelons

• To get the best results from growing seedless watermelons, the Purdue University Department of Botany and Plant Pathology recommends starting the seeds indoors for later transplant into your garden. Plant pathologist Daniel S. Egel warns that you must provide very strictly controlled conditions for the first 48 hours to promote the germination of seedless watermelons. These include warming the soil mixture to 85 to 95 degrees before planting; lightly watering the soil by misting, as it is very easy to overwater this type of melon; and planting the seeds with their pointed end facing sideways to prevent distortion in the seedlings.