Raised Garden Beds: Galvanized Metal vs. Wood

Raised garden beds are superior to in-ground gardens for a multitude of reasons. They are favored by gardeners worldwide because they offer better control over growing conditions, more comfortable ergonomics, and protection against pests and weeds. Raised beds also help create a better organized and more manageable garden landscape.

The term "raised beds" is often associated with images of wood planter boxes. While wood is undoubtedly a common choice for garden beds, galvanized metal frames are becoming increasingly popular among gardeners. 

If you're considering building a raised garden bed, you may wonder which material to choose. Should you go with galvanized metal or wood? 

Your choice of material heavily depends on your personal preference, climate, and budget. Both wood and galvanized metal have their benefits, but it's essential to consider your needs before making a decision. In this blog post, we'll compare galvanized metal and wood raised garden beds, so you can decide which is best for your garden.

Choosing the best material for your raised garden beds

Garden beds can be made from various materials like wood lumber, bricks, concrete, straw bales, and other miscellaneous containers. While using any of these materials for your raised beds is possible, it is important to remember that not all of them are created equal! 

It is also important to factor in aesthetics, everyone has a different taste, perhaps you’re after a rustic vibe for your growing space, or you’re after an industrial look? Whatever style you are after, it is important to carefully consider not just the material you use for your beds, but also what design you choose. 

Image: Red bricks make for an attractive raised bed material

Here are some key things to consider when deciding what materials to use:

Use caution when using up-cycled materials

While we encourage sustainability, some items should not be reused to make garden beds. There are endless amounts of garden "hacks" popping up every day, but no matter how cost-effective or eco-friendly these ideas may seem, it's crucial to be wary of the origins of your materials.

Salvaged wood, particularly that has been treated or painted, should be avoided at all costs. Many of these reclaimed materials, for example railway sleepers, can contain substances toxic to human health and are not worth the risk of potentially contaminating your soil and crops. On the topic of contamination, large tractor tyres make perfect ‘instant beds’ for non-edible plants. You don’t want to plant food crops in tyres due to chemical leaching. 

Determine your budget

This is not always the case, but your budget will often determine the quality of your raised beds. Higher quality materials typically cost more but are almost guaranteed to last decades longer. On the other hand, if you opt to save money by choosing more affordable materials, you may find yourself needing to replace your raised beds sooner rather than later.

Image: You can even make raised beds from sticks for free, however they won't last longer that 2-3 seasons

Consider Durability

Whether you choose wood, metal, or another material for your raised beds, be sure that whatever you select is durable enough to withstand whatever nature throws at it. Durability is critical because your raised beds will constantly be exposed to moisture, outdoor elements, and unwanted pests. It's also important to consider the bed size as the larger the bed, the more soil it will need to support. A durable material is crucial to ensuring that the bed walls remain intact.

Color

An important factor is the color of the raised bed material. A light color will reflect light, helping to keep the soil cooler which is very useful in hotter climates. For cooler climates a darker color may be more favorable as this absorbs heat and can warm up your raised beds in cooler weather helping you get a head start on the season. 

Wood vs. Galvanized Metal Raised Garden Beds

Now that we've covered the top three factors to consider when choosing the best material for your garden beds, it's time to compare the differences between the most common bed types: wood vs. galvanized metal. 

Wooden Raised Beds

Wood is a universal building material and is perhaps the most popular choice among gardeners when it comes to raised bed materials. Wood can be found everywhere, often at affordable prices, and can be used for up to ten years before needing to be replaced.

Image: Wooden raised beds in my kitchen garden in early summer

What makes wood a particularly attractive material for raised beds is that it offers many customization options. Unlike galvanized metal beds that come in predetermined sizes, wood can be cut and configured to your exact specifications. So whether you require extra large beds or one with a unique shape, wood can accommodate all of your needs. Depending on the thickness of the wood used to make your raised beds, it can even be possible to use the edge as a seat!

Another benefit of wood is that it is extremely easy to source and can be much more cost-effective than galvanized metal. A quick search online will reveal a number of options where you can pick up second-hand wood at affordable prices. However, as mentioned before, it is critical to know the origin and possible prior treatment of reclaimed wood before using it in your garden.

Despite the lower upfront costs of wood, it is essential to note that wood will deteriorate over time more quickly than galvanized steel. The average lifespan of wood is between 7 and 10 years, and perhaps even shorter if you live in a humid or rainy climate. If you choose to use wood for your raised beds, select a rot-resistant variety such as cedar or redwood that is almost guaranteed to last 10 to 15 years. Don't forget to use a food-safe organic wood finish to keep your beds in good condition.

Finally, if using wood, ensure the wood is FSC accredited to help look after the world’s forests, or if sourcing from a local timber yard, ask about the origin of the wood. 

Galvanized Metal Raised Beds

There has recently been a surge in popularity for the use of galvanized metal raised beds among gardeners. Although more expensive than wood, galvanized beds are easy to assemble, entirely safe for use, and are guaranteed to last up to 20 years with minimal maintenance.

Image: Metal vego garden raised bed just filled and newly planted

A key benefit of galvanized steel is that it is coated with zinc which protects the metal from corrosion. It won't rot or degrade, making it ideal for use outdoors. The zinc coating is also entirely food safe, giving you peace of mind that nothing toxic is seeping into the soil with galvanized beds.

Another significant advantage of steel beds is that you can choose the color of the metal. If you live in a cooler climate, you can select a darker color which will aid in warming up the soil temperature, and if you live in warmer weather, you can opt for a lighter color to help deflect the heat.

When purchasing galvanized metal beds, they tend to come in small boxes instead of large pieces (like wood), making them easier to transport. You don't have to tie them to the top of your car to bring them home from the store. Plus, they can easily be carried through the house or to an allotment garden which is particularly helpful if you need to move house as you can take them apart and reassemble them at your next home. They are also exceptionally lightweight, making it easy for a single person to move them around, which can be a major advantage if you frequently change your garden layout. It also means the carbon footprint when it comes to buying metal raised beds will be lower per mile for transport compared to heavier wooden beds. 

Their biggest advantage is that they are so easy to assemble. You don’t need any special tools, and only need to use nuts and bolts to put them together. Galvanized beds have curved corners, allowing for simple assembly versus trying to square off corners for wooden beds which also often need saws and screwdrivers for assembly. Now is a good time to mention that it is very easy to have circular raised beds made from metal, but it would take quite the engineering jobs to get the same shape with wood!

Galvanized beds are also better for water retention as wood raised beds can wick water from the soil during periods of dry weather, whereas metal will prevent this from occurring. 

Image: 10-in-1 metal raised bed made to perfectly fit a corner of the vegetable garden

If you are new to gardening, galvanized beds make it simple to choose the size of your bed as the dimensions are already predetermined - no need to cut or saw like wood. It is also easier to get taller beds that maintain strength and can withstand the pressure of the soil inside. Metal beds give you the exact height you need, which can be more complicated to achieve with wood.

So Which Material Should You Choose for Your Raised Garden Beds: Galvanized Metal or Wood

It really depends on your budget and preferences. Consider how long you want the bed to last, what will look best in your garden, and how much you are willing to spend upfront. 

With an unlimited budget, galvanized steel will stand the test of time while providing excellent results. They are also incredibly quick and easy to set up, like the ones from Vego Garden. However, if you prefer a more rustic look, opt for a high-quality wood like cedar that is guaranteed to last 15 years or more.

Wood varieties such as untreated pine are the best choice for gardeners on a budget. You can easily salvage wood for free or pick up affordable pieces at your local hardware store. 

In the end, you can't go wrong with either material. You may actually consider using both galvanized metal and wood beds in your garden, as they both have enormous benefits! For example, metal beds are an excellent choice for perennial plants because they last longer, while wood beds are more economical and can easily be filled with less soil thanks to their lower height.