How do I grow watermelon
Well don't laugh but apparently it's as easy as spitting the seeds out off the porch because one year my kids got a bumper crop there lol.
The same as you would any other melon, Plenty of run room, raise the fruit up on a box so they won't rot on the bottom, keep free of bugs, and insects. Water thoroughly when needed, fertilize. Amend your soil, till the soil, and pull the weeds, your special care will show in the results and flavor. Get an Ortho book on raising gourds, melons, vetgetables, this is a vine growing species, and of course does not grow on trees like fruit. Use seasoned steer manure and dig it in. My dad used a spade digging 8" down to turn it over. before planting. See if you can get it used at the Salvation Army stores or a used book shop.
First, buy seeds from a local source so you get the ones that will grow in your region. Next, read the seed packet and sow the seeds exactly the way described on the packet. You can get your soil tested by your local agricultural agent or garden club, and I highly recommend it since you will know what you need to amend your soil to promote excellent growth. Finally, I would place growing fruit on carpet remnants so they are above the soil and less likely to rot. This is a tip I read about from gardeners who compete in pumpkin/watermelon growing contests. Apparently it works!
Watermelons love the heat, so be sure to check your Zone and start your seeds at the end of spring. Watermelons don't like to be transplanted, so make a hill of dirt and add about 3 seeds in an area where you have plenty of space. They do take up a lot of room.