Growing watermelons at home can provide you with fresh, flavorful, juicy fruit to eat just seconds after it is cut from the vine. To grow the largest melons possible for your watermelon variety, you'll want to ensure you have healthy, thriving plants to grow the fruits on. Pruning is a key part of the ongoing maintenance required to keep the vines healthy.
Look over the watermelon plants you are growing to locate the main stems that grow outward from the center of the plant. Note how the main stem produces lateral growth, which provides energy-producing leaves that also shade growing melons.
Look under the leaves to spot any melons growing along the main stem approximately two months after planting. Select two to three of the healthiest, most uniformly shaped melons to remain on each main stem. Clip off deformed or sickly looking melons using clean hand pruners by cutting their stems just above the fruit, not the main stem.
Check the plant for dead vines, which will appear brown instead of green. Clip these away where they grew up from the ground. Cut away any main stems that have failed to produce fruits at ground level as these vines will rob water from productive vines.
Inspect the surfaces of leaves every couple of weeks for signs of powdery mildew, a white, dusty-looking substance that rests on top of the leaves and can eventually kill off the leaf, stem and plant. Prune away any infected leaves back to a point where the vine appears healthy.
Harvest ripe fruits when the main stem begins drying up in the fall. Prune away the vines that have produced fruit and no longer hold growing melons.
Pruned vines that were free of disease can be composted while diseased stems should be disposed of in the garbage.
Always wash your pruners with mild soap and water after clipping diseased growth to prevent spreading it to healthy growth the next time you prune plants.