Almost every tire gardener tells novices the same thing: If you can't find a soft spot on the shoulder of the old tire, don't bother turning it into a flower pot. Tires need to be turned inside out to make effective planters, and doing so without a yielding section of rubber makes the process almost impossible. Beyond that caveat, tire gardening is fairly straightforward. Whatever your finished product looks like, take pride in the fact that you've turned a castoff otherwise destined for the landfill into a low-cost container for growing colorful flowers or nutritious produce.
Wipe off the tire with a damp microfiber or chamois cloth.
Place the tire on its side, and draw a guide pattern on the top with a grease pencil or crayon. The classic pattern for tire planters looks much like a continuous line of joined triangles.
Cut into the lines with a sharp, nonserrated knife. Keep the blade away from your body. If the tire doesn't cut easily, use another knife or resharpen the blade. Continue until you've cut through the pattern all around the tire.
Remove the cut-out section of tire. The discarded section should look a bit like a sunburst or flower, with an empty center and rubber "beams" or "petals."
Feel along the perimeter of the tire for any section that feels soft or loose. Push in the sides to find a small area that yields under pressure.
Pull the tire to a vertical position and place a bent knee inside the tire, just under where the softest section of tire is.
Press your foot on the part of the tire lying on the ground, and use both hands to begin to turn the tire inside out, starting with the yielding section of the tire resting on your knee.
Put the tire horizontally on the ground. Continue turning the tire inside out. If you meet resistance, press on the interior wall of the tire. Keep tugging and turning. The tire will get pulled inside out one way or another.
Use a degreasing product and old rag to prep the tire planter for painting. Degreasers vary, so follow the instructions on the package.
Paint the tire with spray paint, coating the exterior and the inside scalloped edges of the tire's rim. Let dry.
Set the planter in its ultimate location. Fill with soil, and sow seeds according to package instructions, or plant with annual or perennial seedlings.