Since the metals in our two beautiful planter types can react with each other, gardeners are advised to keep them separate. While they will work fine in the same row, they should not be placed on another bed. Furthermore, weathering steel reacts negatively to the presence of zinc. That’s why you shouldn’t use zinc bolts, casters, or any zinc hardware in your weathering steel planters. If you do, they can quickly corrode around the bolts, reducing the integrity of your beautiful planter over time. Use stainless steel bolts and Corten pots.