Watermelon packs a punch with important vitamins and phytonutrients. The combination of antioxidant vitamins C and A does wonders for the body. They both stop free radicals from causing damage to cells that otherwise lead to many ailments: plaque build up in arteries through the oxidation of cholesterol, increased inflammation, especially in joints, vision deterioration and cellular damage that can lead to mutations in DNA (which can become cancerous). Watermelon is also a great source of the phytonutrient lycopene, which has received much attention for its antioxidant behavior and ability to reduce the risk of many cancers. Watermelon is also a great fruit source of B vitamins, which the body uses to generate energy from sugars, carbohydrates, lipids (fats), amino acids and proteins. Another phytonutrient, citrulline (an amino acid, too) gets converted to the amino acid arginine. Higher levels of arginine are linked to relaxing blood vessels (through increased production of nitric oxide) removing the waste product ammonia and increasing cell sensitivity to the insulin molecule.
Vitamin and Mineral Content
Vitamins – C, A, B6 (Pyridoxine) and B1 (Thiamin)
Minerals – Potassium and Magnesium
Watermelon may help reduce the symptoms or prevent the onset of rheumatoid/osteoarthritis, colon cancer, asthma, heart disease, type II diabetes, erectile dysfunction, and cancers of the lung, breast, prostate, colon, rectum and endometrium.
How to Grow
Watermelon has the same environmental and cultivation needs as other melons (cantaloupe and honeydews) but falls in a different class. (This makes sense, since watermelon looks, tastes and feels so unlike other melons.) Watermelon cultivars have been established that can fit into a range of garden sizes. Some cultivars are even seedless. Note: Watermelon depends more than others on warm sunny weather (+75˚F.) to grow. A few cultivars grow in slightly cooler climates, so check with a local nursery to see what types can grow in your area. See Melons for details on growing.
Besides the pests in the Melons entry, watermelons are vulnerable to aphids and squash vine borers. Deter aphids by planting French marigolds, which attract aphid predators. Squash vine borers are white caterpillars about one inch long. See Summer-Winter Squash for how to control borers.
Watermelon is ripe when it sounds hollow after knocking on it. Store in a cool, shady place to ensure they last as long as they can (2-3 weeks).