Galvanized steel is an underrated material with many advantages, but both wood and galvanized steel have advantages and disadvantages.
Wooden Raised Garden Bed
Wood is one of the world's most versatile building materials and the most popular choice for gardeners around the world, and for good reason. It's cheap and can be found anywhere. While it won't last forever, a wood-frame bed can last a few years before needing to be replaced.
Advantages of using wood
The advantages of using wood for raised garden beds are its price, customizability and general availability. They also have the best thermal properties of all loft bed materials.
Wood is by far the cheapest raised bed material you can use. You can even recycle wood for free from people's curbs, wooden pallets and even old furniture. Of course, you can source your own wood from forest woodlands. But for most gardeners, you'll be sourcing wood from a hardware store, and woods like pine are so affordable that you can even build large raised bed gardens.
Wood is very easy to obtain, no matter where you are, in the city, the countryside, or in the middle of nowhere to grow a survival garden.
Wooden raised garden beds are very customizable. You can trim the wood to the exact size you want, so you can build a loft bed to your exact specifications. Galvanized steel beds, although available in different sizes, are still limited in size and shape.
One of the less often talked about advantages of wood is how good an insulator it is. Wood will insulate the soil better than galvanized steel, making wood ideal for building raised beds with cool frames for winter gardening.
Disadvantages of wooden loft beds
The main disadvantage of using wood is that it does not last as long as galvanized steel. This is especially true if you live in a humid or rainy climate.
Wood will rot over time and may also be eaten by termites or seedling bugs. If you are a DIY gardener, this is not a problem as you can easily replace the planks as needed. However, if you don't want to make a fuss after building your loft bed, you should consider galvanized steel.
Generally speaking, unless you use cedar or mahogany, your wooden loft bed will last up to 10 years.
Types of Wood for Garden Beds
Although wood may be one of the cheapest materials to use for raised garden beds, it all depends on the type of wood you use.
Most gardeners will use untreated pines because they are readily available and very affordable. The downside to using pine is that it doesn't last as long as other types of wood. Untreated pine beds usually last 7 to 10 years. However, if you live in a very humid climate, such as the Pacific Northwest or deep in the South, the lifespan of a wooden raised bed may be shortened considerably.
The most expensive but most durable options are cedar or mahogany. Cedar is also common, but can be very expensive. However, if you can source cheap cedar or are willing to pay more, expect your cedar bed to last 10 to 20 years.
For DIY raised garden beds on a budget, a popular option these days is to repurpose wooden pallets. If you ask individual distribution centers, big box stores, or even check local online ads, you can often get pallets for free. You can also find local pallet recycling centers that can provide you with pallets for free or for a small nominal fee.
If you are using pallets to build your wooden raised garden beds, avoid any colored pallets or pallets with MB printed on them. MB stands for methyl bromide, a toxic chemical used to treat wooden pallets.
Wooden pallets printed with HT (heat treated), DB (peeled) or KD (kiln dried) should be safe to use in the garden.
Galvanized Steel Raised Garden Bed
There is currently a resurgence of interest in galvanized steel as a raised garden bed material, with companies specializing in galvanized raised bed kits that are easy to assemble, safe to use and outlast any type of wood. Galvanized steel beds are expensive, but provide the best long-term, low-maintenance solution for the home gardener.
Advantages of using galvanized steel
Galvanized steel is galvanized steel that protects it from corrosion, making it ideal for any outdoor application. It can take years for it to start rusting, and the galvanized bed will last at least 20 years without replacement and with minimal maintenance.
Galvanized steel will not rot, degrade, and is very durable.
While nothing stops you from building taller raised beds out of wood, galvanized steel bed kits often already have taller versions. Waist-height raised beds are easier to plant, weed, mulch and harvest, especially for older gardeners or gardeners with limited mobility.
Galvanized steel is galvanized steel that protects it from corrosion, making it ideal for any outdoor application. It can take years for it to start rusting, and the galvanized bed will last at least 20 years without replacement and with minimal maintenance.
Galvanized steel will not rot, degrade, and is very durable.
While nothing stops you from building taller raised beds out of wood, galvanized steel bed kits often already have taller versions. Waist-height raised beds are easier to plant, weed, mulch and harvest, especially for older gardeners or gardeners with limited mobility.
Disadvantages of Galvanized Steel
It may seem easy to use a galvanized steel bed, but there is a cost to using galvanized steel.
The first is the literal cost: the upfront cost of a raised garden bed made of galvanized steel is much higher than that of wood. While a 12-square-foot wooden loft bed made from off-the-shelf pine can cost less than $30 and even use salvaged wood for free, a galvanized steel bed of the same size can easily cost you over $100, especially for heavy duty bed.
Galvanized loft beds are not as easy to find as wood. There is very little distance between suppliers, and cleaning your own galvanized steel often means getting steel that has already started to rust.
One situation where a galvanized bed will not last long is in acidic soil. The acid will gradually attack the zinc coating. If you're filling soil for acid-loving plants like blueberries, use plastic-lined galvanized steel.
Finally, galvanized raised beds do little for soil insulation for winter gardening. Yes, galvanized steel heats up faster in the sun, but it also releases heat faster at night.
where to buy galvanized steel beds
You have several options to add to your garden. There are different styles of galvanized steel beds, but I strongly recommend against using any galvanized raised garden bed that uses plastic posts or fittings, as the plastic will degrade or crack long before the galvanized steel.
Instead, look for an all-steel design or one with a wood frame or columns. At least for wooden frames, they will be easy to replace over the life of your raised garden bed.
Birdies would be my pick if you're in the US or Australia (they also ship to Canada). I'm not affiliated with Birdies, but you can see galvanized steel garden beds in action on the SelfSufficientMe channel:
Should I use galvanized steel or wood for my loft bed?
In the end, it really depends on your situation and budget.
If you're on a budget, either cedar or galvanized steel will work well. It's all a matter of style. Some people like the rustic look of a wooden raised bed, while others like the industrial look and finish of corrugated galvanized steel.
For those on a budget, you can't go wrong with wood. Wooden loft beds are easy to build, and you can even salvage wood for free. Wood also allows for more design flexibility and customizability.
If you live in a humid climate, galvanized steel offers a more durable, longer-term solution.
Gardeners who don't want to make a fuss about raised beds or have limited mobility can also opt for galvanized beds, as they can last for decades, and many come standard with 2- or 3-foot beds, making it easier to grow and maintain your vegetables and flowers.
