Step 3: Grab a root and growl...
6.) Though you are only going to cut half of the circle you've drawn, I prefer to then cut between each petal down to the very edge of the steel belt (if present) but do not cut into the belt. Just cut a slit between each petal as shown. It helps they petals lay right and makes things easier when flipping the tire inside out.
Now here comes the hard part, bear with me, folks.
No matter how I show you or explain this to you, if you didn't start with a tire that had a sweet spot, you may as well wrestle a Grizzly bear instead, because you will exert the same amount of energy. Keep in mind, this project was completed by a slender woman, so if I can do it, you should be able to do it.
7.) Practice, practice, practice. Each tire gets easier once you figure out there truly is a trick to getting the turning started and completed. Using both hands, pull on a petal in each hand while using your knee to push in on the tire. It should easily give and fold the right direction. How you complete this is now your option. You can use your knee, you can sit on the darn thing and push with your foot, you can stand it up and use your foot...anything to get it moving.
8.) Very important! Once you get a two-petal flip going, move slowly along the tire raising another petal or two, pushing and pulling the tire as you go. Don't try to move all around the tire or try to use brute strength to just flip it inside out. Let the tire work with you by moving slowly along the flip you've already started.
And even though you may have the tire halfway flipped, that was the easy part!
9.) Once the tire has been turned inside out, sit down and catch your breath.
If it was that easy, get started on another.
If it was that hard, next time search for a more worn tire.
After the resting period is over with, now spray your tire down very well with a good degreaser or a heavy coating of Simple Green. A good scrubbing brush is pretty handy in this step. Rinse well and allow to dry.
You can now use your tire planter as is, or paint it. To paint, simply use a can of spray paint, or if you want to get fancy, use canned paint. If you are using the tire as a planter, you won't need to paint the inside of the planter, as this is where soil will be, so paint the petals and just below them.
With regard to using these tires for food, there is way too much of this discussion on the internet to start it here. I'm not going to get into whether you should or should not plant food items in these tires. That is something you will have to research and decide for yourself.