I have an old tire in the chicken play yard for them to jump up and down on in the shade, and a half tire planted in the potted garden with some squash.
Once melons start to show up on the ground, I use Dollar Store colanders to keep them off the dirt while they grow. And I often will put a juice jug that's been washed out and punched with a small hole or two near a plant that needs more water, so that it will be released slowly over time. This gets even more important as our hot Texas summer gets going.
Think before you throw anything away -- it may be very "U"seful in your garden!