Our show planter at the Oslo Garden Show was manufactured from the popular Cor-Ten steel. Cor-Ten steel eliminates the need for painting and produces a rust effect layer. Despite appearences Cor-Ten makes the the steel less susceptible to corrosion.
A disadvantage to all metal planters are that they can get hot in the summer sun and cold during the winters, consequently, causing heat or frost damage to plants. The solution is easy with polystyrene insulation sheets. The sheets can be easily cut to size to line the inside of a planter. These sheets then prevent the soil from getting too hot in the summer or too cold in the winter.