Watermelon is a summertime favorite for many gardeners. The warm-weather fruit has numerous species, sizes, color,s and flavor, and while they are ideal for warmer climates, the plants can also thrive quite well in cooler areas. You can successfully grow melons in hardiness zones three through eleven, though the cooler zones require a little more effort in extending the growing season.
While the fruit is delicious, it also packs heavy amounts of vitamins A and C, as well as powerful antioxidants, potassium, manganese, magnesium, and copper. Watermelons also have smaller amounts of calcium, iron, phosphorus, selenium, thiamine and vitamin B6.
Watermelon plants grow best in a soil that measures between 6.0 and 6.8 on the pH scale. Well-drained soil is essential for these fruits, and the plant roots require fully cultivated, aerated beds in order to take hold. Thorough fertilizing is also ideal for these plants, and this can be done after soil is cleaned of any rocks, sticks, or debris. Apply compost or organic compound fertilizer to ensure the best possible yield and quality of watermelon. In colder climates, cover your soil with black plastic a few weeks prior to planting; this will warm your soil in preparation for seedling transplant.
Smaller varieties of watermelon usually produce fruit in about seventy-five to eighty-five days, while the larger species of the fruit typically require eighty-five to one hundred days. These plants, regardless of species, will need to be planted indoors except in warm climates. The seeds cannot be planted directly outside until the soil has reached seventy to eighty degrees Fahrenheit.
Use peat pots that are about four inches in diameter for sowing your seedlings two to four weeks prior to transplanting them outdoors. Plant several seeds about half an inch deep in each pot, and water well; seedlings should be placed in a warm and sunny window.
Seedlings will need to be hardened off prior to transplanting, and this process should begin seven to ten days beforehand. Place your seedlings outside in the shade for three to hours on the first day, and add one to two hours of outside exposure each day. On the third day, introduce sunlight. Keep your plants in a sunny warm spot during the morning and move to the shade in the afternoon. Bring your plants in overnight. By the seventh day, your watermelon plants should be ready for transplanting into your garden.
Hills within the soil should be prepared prior to transplanting your seedlings. This will ensure an appropriate amount of drainage; row spacing will depend on the type of watermelon plant you are working with. For fast-growing or larger melon plants, hills should be placed between six and twelve feet apart. For average, slow-growing, or smaller melons, rows can be placed between four and six feet apart.
Spacing of the seedlings is also determined by the size of the mature fruit of the plant. If you have plants that produce larger melons (anything over eighteen to twenty pounds), place your seedlings four feet apart. For smaller melon plants, two feet spacing should be sufficient. Maintain regular and consistent watering of at least one inch per week.
Bloom rot is a consistent problem in growing watermelon plants; this is often caused by a lack of calcium in the soil. Regular watering should provide enough calcium, however, crushed eggshells can be added to the soil to aid this deficit as well.
Cucumber beetles are particularly damaging to watermelon plants. Planting radishes near your watermelon can help deter these pests and keep them off of your plants.
It can sometimes be difficult to tell when watermelon is ready for harvest; however, the plant itself can give you some important clues. The curly tendril where the stem meets the vine should be browning or even dead prior to picking the fruit. The bright green of new watermelon fruit will fade as the melon matures. Ripe melons should be a dark, dull green with a creamy or yellow belly. Cut the stem from the vine to harvest.
Watermelon can be enjoyed fresh as is, as well as in salsas or salads.