If you’ve ever considered using corrugated metal raised beds in your garden, you’ve probably asked yourself: “Do they rust?” It’s a fair concern. After all, no one wants their beautiful vegetable patch or flower garden tarnished by rusty metal. This article digs into this topic and uncovers how these raised beds hold up over time.
Why Choose Corrugated Metal Beds?
Corrugated metal beds are loved for their durability, sleek modern look, and ability to warm the soil quickly in cooler climates. They’re a practical and stylish option for gardeners who want something long-lasting without the risk of rotting like wood.
But as durable as they are, they’re still made of metal, and metal plus moisture can equal rust. So, what’s the verdict?
The Truth About Rust
Yes, corrugated metal can rust, but the extent to which this happens depends on the type of metal used and how it’s treated. Most corrugated metal beds are made from galvanized steel, which is steel coated with a layer of zinc. This zinc coating is a protective barrier, preventing rust from forming on the steel underneath.
Over time, however, the zinc coating can wear away, especially if the bed is exposed to harsh conditions like heavy rainfall, salty air, or acidic soil. When the zinc layer is compromised, the steel underneath can start to rust. But don’t worry—this process typically takes many years, and there are ways to slow it down even further.
What Affects Rusting?
● The Type of Metal
You’re already ahead of the game if you’re using galvanized steel (which most corrugated panels are). The zinc coating acts like a shield, protecting the metal underneath from rust. Some gardeners get 15-20 years or more from their galvanized beds before seeing any significant rust.
● Climate
Living in a rainy area or somewhere with high humidity? Your beds might rust faster than those in drier climates. Salt air near the coast can also speed up rusting.
● Soil Contact
The place where metal meets soil is where rust typically starts first. This is completely normal and isn’t as problematic as you might think. This minor rusting adds iron to their soil – a nutrient many plants love!
Tips to Prevent Rust
If you want your corrugated metal raised beds to last as long as possible, here are some tips to help prevent rust:
Choose High-Quality Materials
Look for beds made from thick, galvanized steel or those with an additional powder coating. These materials are designed to resist rust and withstand the elements better than plain steel. Look for metal that’s at least 26 gauge thick—it’ll hold up better over time.
Add a Liner
Installing a plastic or landscape fabric liner inside your raised bed can create a barrier between the metal and the moist soil. This reduces the chances of the zinc coating wearing away and exposing the steel to rust.
Ensure Proper Drainage
Standing water accelerates the rusting process. To prevent water from pooling at the base, make sure your beds have good drainage. Adding gravel or sand to the bottom of the bed can help with this.
Place Your Beds Strategically
If possible, position your raised beds in areas that aren’t constantly exposed to water, such as near a sprinkler system or under a leaky roof.
Touch Up Any Damage
Rust can set in faster if the galvanized coating gets scratched or chipped. Keep an eye on your beds and touch up any damage with rust-resistant paint or sealant.
What If They Do Rust?
Even if your corrugated metal beds develop a bit of rust over time, it’s not the end of the world. A little rust is mostly cosmetic and won’t affect the bed’s structural integrity for many years. Rust is simply iron oxide – a natural compound in most soils. The amount of rust that also develops is typically very small and won’t affect your plants or food safety
If the rust bothers you, remove it with a wire brush and apply a rust converter or sealant to stop further corrosion.
Are Corrugated Metal Beds Worth It?
Absolutely! The potential for rust shouldn’t deter you from using corrugated metal beds in your garden. Their durability, versatility, and aesthetic appeal far outweigh the risk of rust. With proper care and maintenance, they can last 10 to 20 years or even longer, making them a worthwhile investment.
