EarthTainers?

[Toothless_Kitty]

I keep seeing folks talking about Earthtrainers. I have a roof garden and that sounds good to me. Could someone point me twords a good starting point for understanding how they work and how to build them? Like Earthtrainers for Dummies. My husband and I are both handy so construction should be no problem. That is after he finishes making "The Face". That's the one he gets every time I come up with a new project. It comes right before the trip to Home Depot.

Thanks, Laura