If your watermelon plant is not growing well, here are a few problems that could be the cause: -If you’re not using loose and organically rich soil to sow the melon seeds in, your plant won’t grow properly.  -CUT THOSE WEEDS OFF. They’re not as harmless as you might think; they can invade the melon roots and stunt their growth. -Overwatering or underwatering. Watering correctly is crucial for growing watermelon, so make sure you’re watering as necessary.  -Check the plant for pests and diseases. Ignoring such issues can seriously affect the development of your watermelon plant.