Watermelons can be a great crop for home production, as well as commercial production.
What to Know
Like most crops, watermelons should be planted on a well-drained site, and should not be planted in a low spot that is susceptible to flooding or on land with poor internal drainage. It takes time, but growing cover crops is a great way of increasing the organic matter and improving internal drainage of a field.
Watermelon is in the cucurbitaceae family which includes cucumber, muskmelon, squash, pumpkin, gourd, and honeydew. It is very common for plants in the same family to share diseases, making it very important to rotate crops. If possible, it is recommended to wait up to five years before growing a crop such as watermelon in the same place as any other crop from the same family. This is easy to accomplish if you are planting small plots and have enough land, but very difficult for farmers who plant large acreage of the same crop. If crop rotation is not possible, Extension professionals recommend planting watermelons with the most disease resistance possible. Some watermelon varieties offer resistance or tolerance to certain diseases including fusarium wilt race 1, anthracnose, and powdery mildew.
Of course soil testing in advance of planting is recommended along with growing cover crops. It is beneficial to conduct soil testing in the late summer and apply any needed lime when planting cover crops. Growers already know how much nitrogen, phosphorus, and potassium watermelons need, but do not know which elements are already present in the soil. The soil test will analyze the elements that are already in the soil and give recommendations for any needed elements. The Extension office can explain how to take soil samples and answer questions concerning the soil test results.
Spacing and Light Needs
Plant spacing for watermelons is related to the desired size of the melon. Larger fruited melons are generally given 24 to 30 square feet per plant. It is common to see watermelon rows spaced 6 feet apart with plants spaced 42- to 60-inches in the row. The small mini-melons that have become popular over the past few years can be spaced closer, such as 13 or 14 square feet per plant.
Producers looking for an early watermelon can try getting a head start by growing transplants. Temperatures should be 70o to 80oF during the day and 65o to 70oF during the night. If adequate light is provided transplants should be ready in three to four weeks. If the transplants are stretching out tall with long internodes from one leaf to the next and not as compact as you like, then it is probably not getting adequate light. Sunlight is best, but supplemental light can be added. Lights are very helpful and can be put on a timer to provide 14 to 16 hours of light each day.
Varieties of Watermelon
Some recommended seeded watermelon varieties include ‘AU Producer,’ ‘Crimson Sweet,’ ‘Jubilee II,’ ‘Jamboree,’ ‘Lemon Krush,’ (yellow flesh), ‘Sangria’, ‘Sentinel’, ‘Starbright’, ‘Summer Gold’ (yellow flesh), and ‘Top Gun.’ A couple of recommended icebox/mini melons are ‘Mickey Lee’ and ‘Sugar Baby.’ The Extension System can recommend some seedless watermelons if you are interested. If you have any questions, give us a call at your local Extension Office.