Hill or row?
Some gardeners like to position three or four watermelon plants together in a clump or "hill," spacing their hills 6 to 8 feet apart. Other watermelon growers space individual plants 2 to 4 feet apart in conventional rows.
Weeding is easier with the hill method. But if you water with soaker hoses or drip irrigation lines, planting in rows will be easier.
That's why they call it watermelon.
As much as 95 percent of a watermelon's weight is water. Regular deep watering is especially crucial during the first 3 to 4 weeks that the vines are growing in your garden. Cut back on the water once the plants have begun to set fruit; overwatering dilutes the melon's sugars and makes the flavor weaker and less sweet.
Drip irrigation or soaker hoses are the best
way to give watermelons a steady supply of moisture. And in humid climates, watering the roots directly rather than soaking the leaves, too, helps prevent many common foliar diseases.
Mulch with straw.
A thick layer of straw around your melon vines not only keeps the soil evenly moist and obstructs weeds from sprouting, it also prevents the melons from direct contact with the soil, further reducing the risk of diseases that may splash up from the soil.
Look for resistant varieties.
Fusarium wilt and bacterial wilt are two prevalent watermelon diseases. The best ways to avoid these diseases, which are typically not curable, is to look for disease resistant varieties.
Pests? A couple.
Cucumber beetles typically prefer cucumbers and muskmelons, but they will occasionally feast on watermelons, too. Insecticidal soap is a safe, effective treatment for most cucumber beetle infestations. If you've endured major cucumber beetle attacks in the past, keep them from getting to your vines with row covers—just be sure to remove the covers when the vines begin to flower so that bees can pollinate them, which is necessary for the plant to set fruit.
Squash vine borer larvae tunnel into watermelon vines, chewing inner tissue near the base and filling the stem with moist, slimy castings. The attacked vines wilt suddenly and girdled vines rot and die. Again, row covers are the best defense, according to Rodale's Pest and Disease Problem Solver.
When are the melons ripe?
Experienced watermelon growers try a lot of tricks to know exactly when the fruit is ready to eat. Here are a few you can try:
- When the tiny tendril on the vine just opposite of where the watermelon stem attaches dries out and turns brown, the melon is ripe.
- "The flat dead sound emitted by a melon when thumped is the readiest indication of ripeness, and the one most universally depended on," says 1,001 Old-Time Garden Tips. "If the resonance is hollow, ringing or musical, it is certain proof of immaturity."
- Rinds of unripe watermelons have a nice shiny gloss; ripe melons lose that shine, so the rinds are drab.
- The spot where the melon rests on the ground turns greenish-yellow as the melon reaches maturity.