I don't know why, but I have an abnormal love of things that look like food but aren't actually food. While the flower pot I made is a bit small for growing an actual watermelon plant, you can use the same technique for a larger pot, preferably at least 7 gallons. Affiliate links below.
Decoupage Watermelon Flower Pot
Paint the entire clay pot, inside and out, with a coat of gesso. When that is dry, paint the pot red and the saucer green.
Tear the two shades of green tissue paper into strips. Put a coat of Mod Podge on the inside of the saucer, then add strips of light green radiating out from the center. Paint each strip in place with more Mod Podge. Then add dark green strips to fill gaps between the light green.
As an aside, you'll see classic Gloss Mod Podge in the photo above. A few minutes after I took this picture, I realized that a flower pot needs to be waterproof. So I switched to Outdoor Mod Podge for the rest of the project.
Speaking of Mod Podge, this beloved craft supply turned 56 on Friday! Since I'm 51, it's no wonder I feel like Mod Podge has been around forever. On Friday, I took a quick photo of my paint shelves and discovered I have 17 different types of Mod Podge within easy reach. Believe it or not, there are more bottles in my craft closet.
When you have decoupaged the inside of the saucer, let it dry completely and start covering the inside of the pot with red tissue paper. I like to put projects on these paint stands while they're drying.
Use the same process as before to decoupage the underside of the saucer and the outside of the pot. You can add as many (or few) layers of tissue paper as you want. Use scissors to cut teardrop shapes from the black tissue paper and decoupage them around the rim of the pot. Let everything dry completely, then add an additional coat of Outdoor Mod Podge to make sure it is completely sealed.
Since my watermelon flower pot is too small for growing healthy watermelons, how will I use it? It'd be great for growing smaller plants, like flowers or herbs. Or, it would make an adorable container to hold plastic silverware or whatnot for an outdoor BBQ or party. I made a piñata for a strawberry-themed party years ago; this could be the inspiration for a watermelon-themed party. Lots of possibilities!