How to Grow Watermelons in the South

Use a home soil pH test kit to test the pH of the soil where you will be planting your watermelons. Dig a small hole approximately 6 to 8 inches into the soil, and collect a soil sample. Place the sample into the enclosed test tube. Fill the test tube with distilled water. Cover the tube with the cap and shake well. Allow the soil to settle, and dip the pH strip into the water. Compare the color on the test strip to that on the pH chart. Watermelons grow best with a pH between 6.0 and 6.8.

Add 1/10 lb. of elemental sulfur for every 100 square feet to lower the soil by 0.5. Wait three months before applying more sulfur to the soil.

Add 3 lbs. of limestone for every 100 square feet of soil to raise the pH by 0.5 in sandy soil. Add 6 lbs. of limestone in clay soils.

Plant watermelon seeds in late spring after the last threat of frost. Pull soil up from the surrounding area with a hoe to create a small hill approximately 4 to 6 inches in height. Place four or five seeds into each hill. Plant at a depth of 1 inch, and place hills 6 feet apart in rows. Space the rows at least 7 feet apart. Thin the seedlings to the three hardiest plants. Discard the remainder of the vines, or transplant them to another location in the garden by digging a shallow hole and placing the plant roots inside. Cover with native soil.

Hoe the weeds around the watermelon plants at least once a week so the vines do not attach themselves to the weeds and the weeds do not choke out the watermelon plants.

Water your watermelon plants once a week with 3 to 4 inches of water.

Harvest watermelon when they are fully ripe. The stem will turn dark brown and will appear dry, and you will notice green tendrils on the stem near the fruit. Listen for a dull thud when you tap the center of the melon. Cut the watermelon from the stem using a sharp knife.