ill the soil. Use a tiller to work the soil for the beds thoroughly, breaking up large clumps of packed earth. Remove any vegetative matter or deeply incorporate it into the soil.
Watermelons like loamy, fertile, well-drained soil. To determine whether your soil gets good enough drainage, take a look at it after a heavy rain. If you see puddles in the dirt, the soil isn't draining well enough.
To further enrich the soil, till compost into the top of layers.[2]
Watermelons grow best in soil with a pH of 6.0 to 6.8. Test the pH of your soil and determine whether the levels are appropriate for watermelon plants. If not, you can change the balance by adding compounds available for purchase at a plant nursery.