Are Galvanized Raised Garden Beds Safe? - Backyard Boss
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Are Galvanized Raised Garden Beds Safe?

Regardless of how much space you have for gardening, there are many ways to grow your favorite plants. You can garden indoors, outdoors, directly into the soil, in containers, or raised garden beds.

By definition, raised garden beds are customizable boxes that you can place on top of the garden soil. They help fight soil erosion, prevent an explosion of weeds, and keep most pests at bay. Apart from that, raised garden beds have better drainage, are easy on your back, and are great for older gardeners or those with mobility issues.

While many raised beds are constructed of wood, bricks, and rocks, galvanized steel raised beds are becoming an exceedingly popular option. So, are galvanized garden beds safe? Below you’ll learn what you need to keep in mind when working with this material.

Is Galvanization Dangerous to the Environment?

galvanized raised garden bed
Image credits: mikecogh via Creative Commons

Corrosion is a natural process that, unfortunately, weakens the metal. To prevent rusting, a layer of zinc is applied to the metal to avoid this inconvenience. This process is known as galvanization. Since zinc corrodes faster when exposed to electrolytes, it essentially sacrifices itself for the benefit of the primary metal, helping your raised garden beds last longer.

Now, the main question: Is galvanization dangerous to the environment?

Zinc can be found in everyone, specifically 1.4 to 2.3 grams in the average adult. While zinc is a natural component, heavy exposure can cause stomach cramps, skin irritation, nausea, and vomiting, while extreme cases can cause respiratory disorders. Even small exposures from a work place environment can leave some feeling like they caught the flu.

When it comes to gardening, it would be best to use rainwater. Using water polluted with zinc raises acid levels in the water, which finds its way into our bodies through the veggies and fruits grown for consumption.

That said, although zinc corrodes faster, it takes a long time to reach a stage where it stops offering protection to metal. It takes more than 50 years for zinc to corrode; hence it requires little additional energy and produces little waste.

Zinc adds to sustainable development, can be recycled, and has a minimal environmental impact. The main concern is cleaning up after galvanization to prevent zinc from polluting water bodies used for farming fish or water crops for consumption.

Is Galvanized Steel Safe For Gardens?

galvaized raised beds
Image credits: mikecogh via Creative Commons

Yes, galvanized raised garden beds are safe if you maintain them to avoid zinc and metal leaching. As you learned above, zinc is a natural component that exists all around us. However, high concentrations can lead to some health issues.

After building or purchasing your galvanized raised garden bed, test your soil’s pH levels to ensure the soil isn’t acidic. This is because acidic soil will break down the zinc and increase zinc levels in the soil. While small amounts of zinc can serve as micronutrients, large amounts can find their way into the crops you’re growing for consumption.

If your soil is acidic, add lime, wood ash, bone meal, or ground eggshells to make it alkaline. Does this mean you’re doomed to grow only alkaline-loving plants in your galvanized raised garden bed? No, of course not! You can use plastic-lined galvanized steel to grow acid-loving plants like blueberries, onions, and hydrangeas.

Although galvanized metal plates are said to be sustainable for decades, your raised garden beds have been constantly exposed to the elements. If you’ve had galvanized raised garden beds for sometime now, around 15 years, keep an eye out for rust.

If you spot some rust, don’t panic. Instead, line your raised bed with greenhouse plastic or any other material that allows good drainage. This will put a barrier between the soil and the rusted metal.

Then again, if a large amount of your galvanized raised bed has rusted, it’s better to DIY a new one.

How to Maintain Them

three raised beds
Image credits: mikecogh via Creative Commons

As you learned above, the biggest concern with using galvanized raised beds is the clean up, and growing acid-loving plants. Your raised beds will be fine if you use heavy plastic liners to avoid direct contact between acidic soil and the metal. Don’t forget to add mulch to improve your raised bed’s water retention ability.

If you’re not using your galvanized raised bed to grow acid-loving plants, don’t instead grow them on the ground too close to the steel bed. This is because you’ll likely use acid-based fertilizers to help them thrive, which will react negatively with your raised bed.

Why They’re Popular

round galvanized raised beds
Image credits: mikecogh via Creative Commons

Galvanized raised garden beds are becoming popular because they’re incredibly sturdy and resistant to damage. Some gardeners switched from wood to galvanized steel beds because, unlike the former, they won’t rot and will last for many decades if maintained properly.

Furthermore, galvanized raised beds don’t require as much maintenance! You can say goodbye to the hassle of oiling and painting them and rest assured that they won’t swell or contract.

Contrary to popular belief, galvanized raised beds will not heat or bake your plants. Black containers and pots absorb heat, whereas galvanized beds reflect heat. The soil against the sides of the steel bed may be warmer than the center, but that actually works in your favor, especially in spring.

Since the soil in galvanized raised beds warms up faster than the soil on the ground, you can start planting your crops and plants earlier than usual.

Beds of Steel

Raised garden beds are a fantastic addition to any garden. They make the space look nice and tidy and are easy to DIY. You can customize them to fit in any spot in your yard. Furthermore, they keep pests at bay, prevent weeds and help fight soil erosion.

Hopefully, this article was helpful to you. Leave your experiences, thoughts, and questions in the comment section, and as always, please share!

Happy gardening!