A juicy slice of watermelon (Citrullus lanatus) makes for a perfect, refreshing treat on a warm summer day, and if you're responsible for growing it, the experience is even more rewarding. "Carolina Cross #183" is an oblong, striped, red-fleshed watermelon variety that can weigh up to 200 pounds. After a long growing period of about 95 days, you might need some extra hands to harvest this heat-loving, giant member of the Cucurbitaceae family.
Provide "Carolina Cross #183" with a sunny area in the garden that has well-drained, fertile soil with a pH between 6.5 and 7.5. Perform a soil test to determine which amendments to incorporate into the top 7 inches of soil to reach the desired pH. Test the soil early in the planning process, because amendments, such as limestone, which raises the pH, and sulfur, which lowers the pH, can take as long as a year to have an effect. Before starting the seeds, incorporate 3 inches of well-rotted manure into the soil to promote drainage.
Direct-sow the seeds after the soil has warmed to 65 degrees Fahrenheit. Plant two to three seeds at a depth of 1 inch in hills that are spaced 12 feet apart in all directions, because the large vines need space to grow. Keep the soil moist and after germination, thin to the strongest seedling. Alternatively, start the seeds indoors in individual, biodegradable containers about one month before transplanting. Place a heat mat set at a temperature of between 70 to 90 degrees Fahrenheit under the pots to trigger germination.
Give "Carolina Cross #183" about 1 to 2 inches of water per week during the growing season. Adjust your watering frequency after rainfall or during hot, dry spells. Ideally, use drip irrigation so the foliage doesn't get wet. Water the soil deeply and keep it moist. As the fruit ripens, reduce the amount of water and allow the soil to partially dry before watering again.
Side-dress the vines before they start spreading with a 33-0-0 fertilizer at a rate of 1 pound per 100 feet of row. Dig a shallow trench along the length of the row and distribute the fertilizer in the trench. Backfill the trench and water it to bring the nutrients into the soil. Repeat this fertilizer application after the vines bloom and fruit development begins.
Cultivate the soil around the plants regularly and shallowly to avoid damaging roots close to the surface. Aim to keep the soil around the plants weed-free, and if you must, pull weeds out manually as the plants get bigger.
Spread a 2-inch layer of organic mulch around the watermelons after the soil has warmed to 75 degrees Fahrenheit. Use wood chips or straw to combat weeds and promote soil moisture retention. Keep the mulch several inches away from the stems of the plants.