Melon: A Growing Guide

This sweet summertime snack tastes better when it's homegrown.

Growing guidelines: If you’re not using paper mulch, apply several inches of organic mulch just as the vines start to elongate. This covering will suppress weeds and help keep the fruits clean and disease free. Provide generous amounts of water, particularly right after transplanting and as the fruits develop. 
Male flowers appear first, at leaf joints on the main stem and on larger side shoots. Around a week later, fruit-producing female flowers form on secondary side shoots. Despite the many female blossoms, each vine will produce only three or four melons. Most young melons will grow to the size of an egg, then shrivel as they send their nutrients back into the vines. Fertilize with compost tea when the fruits set and again 2 weeks later. 
Though melon vines look very robust, they are actually quite delicate—always handle them carefully. If they start to sprawl outside the area where you wish them to grow, gently guide them back toward the center of the planted area.
In areas colder than about Zone 7, remove flowers and smaller fruits from the vines after midsummer; these won’t have time to mature before frost, and they use up energy that should go into ripening the two or three larger fruits you’ve left on each vine.
Problems: Striped and spotted cucumber beetles can be serious pests. The beetles, which spread bacterial wilt as they feed, tend to be more destructive to direct-seeded plants than to transplants. They often attack around the time the plants flower. Tents of cheesecloth, mosquito netting, or floating row covers are the best protection from beetles, but you must remove these coverings when female flowers form so that bees can pollinate them. Spraying young plants with kaolin clay may deter beetles from feeding. You can also use a hand-held vacuum cleaner to remove beetles from the plants (dump the collected beetles into soapy water to kill them). As a last resort to fight a cucumber beetle infestation, spray a pyrethrin product. 
Melon aphids can also be a problem.
Squash vine borers, which eat their way up the stem of a plant and cause the leaves to wilt, may also attack melons. See the squash growing guide for information on this pest.
Resistant cultivars and crop rotation are the best defenses against melon diseases, including downy and powdery mildews. Mildews are common in wet weather. Downy mildew produces yellow spots on leaf surfaces, with purplish areas on the undersides. Powdery mildew causes powdery white areas on leaves and stems. Even a small amount of mildew can affect the sweetness of melons because the fungus will siphon off the vine’s sugar to fuel its own growth. Sprays of potassium bicarbonate (or baking soda) can help prevent powdery mildew. Cut off and destroy any affected branches.
Bacterial wilt produces limp leaves and stems that secrete a white sticky substance when cut. Remove and destroy affected plants. Reduce the chances of bacterial wilt by controlling cucumber beetles and aphids.
Harvesting: The stem of a vine-ripened fruit should break cleanly with no pressure at all on the stem; just picking up the fruit should be sufficient. You can often judge the ripeness of cantaloupes and muskmelons by scent alone. 
Some gardeners determine the ripeness of a watermelon by thumping it, with a resulting ringing sound if it’s green and a dull or dead sound if it’s ripe. However, a dull or dead sound can also mean that the fruit is overripe. Other growers harvest when the “pig’s-tail” curl where the watermelon attaches turns brown, but on some cultivars this tail dries up at 7 to 10 days 380before the fruit is ripe. Instead, look at the bottom surface or “ground spot” on a watermelon. If it has turned from a light straw color to gold, orange, or rich yellow, it’s ripe for picking. 
Storage time for various melons kept in a cool place can vary from 2 weeks for a cantaloupe to 8 weeks for a casaba.