Botanically watermelon is a warm-season fruit, though as a member of the cucurbit family of gourds, it is grown and harvested as a vegetable.
Most believe watermelon originated in the deserts and semitropical regions of southern Africa. Hieroglyphics found on the walls of ancient Egyptian buildings depict the first watermelon harvest occurring nearly 5,000 years ago.
Today, watermelon is grown around the world and its composition is up to 95% water, hence its name. Rinds, whether solid in color or striped, look hardy but are quite fragile and require picking by hand at harvest.
Interestingly, watermelon is completely edible: the flesh is sweet and juicy, the seeds can be roasted, and the rind can be used for making preserves, pickles, and relish.
Types & Varieties
There are several hundred varieties of watermelon grown in the United States and Mexico. The most common are Seeded, Seedless, Mini, Yellow, and Orange, with many popular cultivars within each category. Rind and flesh colors can vary, as well as both size and shape.
Top growing regions in the United States are Florida, Georgia, California, and Texas. Prevalent seeded varieties grown in these states and elsewhere include Calsweet, Fiesta, Royal Sweet, Sangria, Sultan, and Tiger.
Seedless varieties, which continue to gain in popularity, include Cotton Candy, Crimson Trio, Fandango, Fire Cracker, Genesis, King of Hearts, Nova, Scarlet Trio, Super Cool, Summersweet, Sweet Slice, and Tycoon.
Mickeylee, Palm Melon, Precious Perfection, Precious Petite, Solitaire, and Sugar Baby are popular miniature watermelon varieties. Crimson Sweet and Charleston Grey varieties produce larger, more traditional melons in both Florida and Georgia, along with Florida Giant and Sweet Favorite in Georgia.
Lesser known though gaining converts are yellow-fleshed varieties, which include the aptly-named Summer Gold, Yellow Baby, and Yellow Doll. Gold Strike is an orange-fleshed variety.
Watermelon should be planted after the danger of frost has passed and soil is warm. Plants tend to grow best in air temperatures between 70°F and 85°F and soil temperatures between 60°F and 65°F. Row covers and black plastic mulch can maintain soil warmth.
Sandy loam is optimal, providing good drainage and nutrients. Growing on ridges will help keep roots dry. Vines require considerable space, so plantings are typically kept 5 or 6 feet apart, with 7 to 10 feet between rows. Crops can be direct seeded or transplanted.
Watermelon should be picked at full maturity (it does not ripen after harvest), when stripes have darkened and sugar content has reached about 10%.
Overly ripe melons will turn mealy with little flavor. Melons must be protected to prevent sunburn. A symmetrical appearance, waxy surface, and lack of bruising are all signs of good quality.