The seedless watermelon is a relatively modern development with increasing acceptance from the home and market gardener. The seedless trait is a result of crossing a diploid (2n) parent with a tetraploid (4n) parent. The seed of the fruit from the female parent is triploid (3n). The plant grown from that seed is unable to develop seeds within the melon. When pollinated by a normal diploid cultivar, the fruit will develop and will have a few empty white seedcoats. Seedless watermelons are of superior quality as the softening of the fruit flesh adjacent to the seed is minimal compared to standard cultivars.
How to Grow Watermelon
eedless cultivars are somewhat more difficult to establish because of their strict germination requirements. They require a constant 85°F for good germination and their initial growth is slow. Your best bet is to start them indoors and transplant them outdoors. For best results use sterile seeding mix and 2 1Ž2 inch peat pots. Transplant out when the soil temperatures are nearing 70°F.
The planting of a pollinator variety, included with your seed packet, is necessary for good fruit development on the seedless variety. One pollinator plant should be started for every three seedless plants. Start them at the same time as your seedless plants. Good bee activity is also necessary for best fruit set. The planting of a good bee attractant plant such as borage may help pollination.
Other tips that will help you produce a crop, particularly in cooler areas, are to cloche with Reemay or cover the ground with black Vispore or Planters Paper to help warm the soil. Wire hoops covered with Gro-Therm can also help to increase the heat units to your plants.
Follow the other cultural directions in the catalog as to nutrition and pest control.