How To Make A Bathtub Out Of Cardboard I Made A Mistake. The Brass Cowboy Bathtub I Wish To Make A Planter Out Of Is Really Copper! Any Suggestions?

I made a mistake. The brass cowboy bathtub I wish to make a planter out of is really copper! Any suggestions? - how to make a bathtub out of cardboard

I have a question, how to create a pot outdoors in a bathtub with old cowboy who thought it was brass, but they have learned that since the copper. Does this change the plants to use, and do what I do to prepare for the metal itself? Thank ya'll!