Used tires in gardening?

Used tires in gardening?

Years ago, someone dumped a truckload of used tires on our land. (Rednecks are awesome!) I have an idea of using those tires as a border for a small raised garden in a corner of my yard. I plan to stack them two high, and make the tires themselves a sort of planter for tomatoes, rosemary, etc. My question is: Is this insane? Am I setting myself up for leaching chemical problems? Thanks for your input!
Just a little cutie to share…

Just a little cutie to share…

pretty in pink!

pretty in pink!

mystery plant ID

mystery plant ID

Here’s a few pictures of tomato plant

Here’s a few pictures of tomato plant

My Room!

My Room!

Cuke “How To” and Photos!

Cuke “How To” and Photos!