answer:Probably not very helpful, but I grew up with a wooden planter that had a copper, waterproof lining in it. I think my mother had it custom-built on a sunny living room window seat. It was probably 4’ x 8’ by very deep. It was next to the piano and when I practiced, I could almost feel the ivy tentacles grope for me. People use copper pots for cooking and especially for hand beating egg whites (the best way according to Julia Childs) so it is obviously non-toxic.