Select a wading pool that is at least 4 to 6 feet across and at least 12 inches deep. Drill holes in the sides of the pool 2 inches up from the ground. Use a drill with a 3/4- to 1-inch drill bit and create at least five holes at equally spaced distances.
Move the wading pool to a location that receives full sunlight exposure, which is where melons grow best. Locate an area where the ground is perfectly level.
Fill the pool with equal parts of topsoil, peat moss and compost until it is 1 inch from the top of the pool. Mix the ingredients up well with a shovel.
Water the soil in the wading pool using a garden hose with a sprayer attachment. Water it until the soil is damp all the way to the bottom of the pool, which you can test by digging down one side.
Measure the entire outer rim of the pool using a tape measure. Put on work gloves and unroll a roll of chicken wire or other metal mesh. Use the tape measure to transfer the pool measurement and cut the wire from the roll using tin snips. Trim the height of the wire until it is approximately 2 feet high.
Insert the wire along the inside rim of the pool, burying it at least 6 inches deep. Connect the two loose ends together with twist ties to hold them in place. The wire forms a trellis that will hold the melon vines inside the wading pool.
Plant the melon vines inside the wading pool at the appropriate spacing and depth for the specific variety. In general, plant watermelons 3 feet apart and plant honeydews or cantaloupes approximately 1 foot apart.
Water the wading pool as needed to keep the soil constantly moist but never soggy.