How to Grow Bigger Watermelons in Louisiana

Select a variety known for producing big fruit, such as "Carolina Cross," "Jumbo Black Diamond" or "Blue Rind." These varieties are often grown for watermelon contests and and can reach 150 to 200 pounds in size.

Spread black plastic over the soil two or three weeks before planting. The black plastic warms the soil so plants grow even more quickly.

Spread 2 inches of compost over the soil and 4 cups of 10-10-10 fertilizer. Till these amendments into the soil to a depth of 8 inches before planting.

Plant watermelons in sandy loam soil, after the soil reaches 62 degrees Fahrenheit and danger of frost has passed. Amend or replace heavy clay soils, which tend to stunt watermelons' growth. Planting time in Louisiana ranges from March through August, depending on your location.

Plant watermelons in full sun, on a gentle slope. Low-lying areas tend to be colder and watermelon won't grow as quickly.

Space watermelon plants at least 6 feet apart. Watermelons need plenty of room to grow vigorous vines and produce large fruit.

Install soaker hoses in the garden area, which deliver moisture directly to the roots and reduce evaporation. In the absence of rain, water melons when the soil feels dry 1 inch beneath the surface.

Pollinate watermelon by hand if bees are scarce in your yard. Use a small paint brush or cotton swab to gently brush a male flower, identified by its long, slender base, to collect the pollen. Transfer the pollen to a female flower, which has a small bump at its base. Avoid using pesticides, which can kill pollinating bees along with pests. Poorly pollinated watermelon plants produce small, inferior melons or might not produce fruit at all.

Place 1 tablespoon 34-0-0 granular fertilizer on the soil 6 inches from each plant. Apply this fertilizer after the plants produce runners. Till it lightly into the soil or water it in.

Control insect and disease problems early. Louisiana's humid climate means disease and insects are a constant issue. Select disease-resistant varieties, rotate crops and keep plants healthy to reduce problems.

Place weed-free straw mulch or cardboard beneath a ripening watermelon to prevent rot or insect damage.