How heavy are cast iron outdoor flower boxes compared to other metals?

Cast iron outdoor flower boxes are significantly heavier than those made from other metals like aluminum or steel. Typically, a medium-sized cast iron planter can weigh between 20 to 50 pounds, depending on its design and thickness. In contrast, aluminum flower boxes are much lighter, often weighing just 5 to 15 pounds for a similar size, while steel planters fall somewhere in between, ranging from 15 to 30 pounds.

The weight of cast iron makes it exceptionally stable and durable, ideal for windy areas or high-traffic gardens where lighter planters might tip over. However, its heaviness also means it’s less portable and may require additional support if placed on balconies or elevated surfaces.

For gardeners seeking a balance between weight and durability, steel or powder-coated aluminum planters might be a better choice. But if long-term stability and a classic aesthetic are priorities, cast iron flower boxes remain a top-tier option despite their heft.