How to Grow Watermelon in a Smart Pot

Prepare a Smart Pot that holds at least 5 gallons of potting soil.

Fill the Smart Pot a little more than three-quarters full with commercial potting soil. Don't use garden soil, which becomes compacted and may contain bacteria, insects and weed seeds.

Mix a slow-release granular fertilizer into the potting soil according to the rate specifications on the label. Withhold fertilizer if the potting soil has fertilizer pre-mixed.

Plant four to six watermelon seeds in the center of the Smart Pot.

Water the watermelon seeds immediately after planting. After that time, water whenever the top 1 to 1 1/2 inches of soil feels dry. Check the plants daily, because you may need to water twice daily during hot weather.

Thin the seedlings to two or three plants when the seedlings are about 2 inches tall. Don't pull the plants. Instead, pinch them off with your fingers.

Decrease watering when the melons are about the size of a baseball. From that time, water only when the vines appear slightly wilted.

Thump the melon firmly with your knuckles to check for ripeness. A ripe melon has a dull sound. Check the melons in the morning while the air is cool because the sound is affected by warm air.

Remove the watermelons from the plant by cutting them with a knife or garden shears. Don't attempt to pull the melon from the plant.