We have repurposed several tractor tires, which at the smallest are 6 ft wide or so and about 16 inches high (or much bigger) once set down on their sides on the ground, for raised gardens, they are perfect for this. They need to be filled with topsoil and compost, then they're ready to plant. The tires should be placed where you want them, and really think about where you want them placed, because they're tough to move once filled with soil. They can be moved, but you will need a tractor. Also Read: how much does a tire shredder cost

We had several of them lined up in rows in a section of the garden, and I planted cucumbers in one, tomatoes in another, green beans in another, etc. A couple of benefits is that they are usually free, and they last decades. Around here people paint them white, I think because the black tires get warm in the sun, and being white repels some of the sunlight. Every so many years they will need repainting, but that's it. You wouldn't have to stick to white paint, you could make garden type designs or do a spatter pattern, or whatever.

I suppose you could use car tires for the same purpose, but you might want to stack 2 or 3 of them for extra height. They could also be used for mulch rings around trees, I'm talking about the small car tires, especially the narrow types, or even bicycle tires. You don't want to be using an 8 or 10 inch wide tire, thats too much mulch. The mulch should be 3 to 4 inches deep , thats all. That way, you're not hitting your tree with the weedeater, you'd be hitting the tire instead.