A perennial summer favorite that inevitably shows up at barbecues and get-togethers, the watermelon comes in many varieties to suit individual needs and tastes. Watermelons thrive in warm areas with plenty of sunlight; however, seeds can also be started in the winter indoors to get a head start on this succulent fruit. The watermelon is an ideal fruit for beginner gardeners with plenty of growing space, since it is easy to grow and relatively maintenance-free.
Select a garden site with well-drained soil that gets good sunlight and air circulation. Prepare it after the last frost in your area by removing weeds and plant debris, and raking the area at least 2 to 3 feet deep to aerate it. Mix equal amounts of compost and manure in a bucket and pour a 2 to 3-inch layer over the prepared area. Rake it in again so it goes deep into the soil.
Purchase seeds of the cultivar you want to grow from your local nursery, or use those if you saved from last season, if any.
Make 6-inch mounds and plant four seeds, 1 inch deep, in the mounds, spaced 6 feet apart. Follow label instructions to apply a slow-release balanced fertilizer to the heavy feeders. You can also sow seeds in peat pots filled with good quality potting soil indoors, and transplant them outside once the danger of the last frost has passed. Seeds will germinate in 10 to 12 days.
Water the seeds at least twice a day, ensuring the soil is moist at all times, until they germinate. Thin seedlings to two per mound per week after they germinate. Cut them off at soil level carefully so you do not disturb the delicate roots of the other seedlings. To do this, grasp a seedling in a few fingers and snip it off with a sharp pair of scissors.
Add a layer of mulch around the watermelon plants to retain moisture; keep the roots cool and prevent weeds from growing around them. Watermelons are not good competitors and will fail to flourish if weeds overshadow them.
Spray watermelon plants with phosphorus rich fertilizer twice during the growing season to promote healthy fruit. Watermelon pests include cucumber beetles and aphids. Hose aphids down, and pick beetles with tweezers to prevent them from damaging your watermelon plants.
Harvest the watermelons 70 to 95 days after sowing seeds. An indication of a mature plant is when the tendrils begin to brown and dry off, and the fruit makes a deep-pitched sound when thumped.
Collect seeds from your watermelon as you eat it and wash them in a mild dishwashing soap. Dry with a paper towel, or place near a window to air dry. Store them in a cool, dry place until the next planting season, when you can sow them for another crop of watermelon fruit.