Last year, my husband Brett and I decided to scrap our old, dilapidated raised beds in favor of new, bigger ones. We made this decision for a number of reasons — our previous beds were never constructed properly, were falling apart, and were not located in the most convenient place. However, all of this lead to a discussion about what kind of materials to use this time around.
And guess what? You get to reap the benefits of our arguments, experience and never-ending thorough research. While we opted for mortared stone, here are the four most common materials used for constructing raised beds, alongs with the pros and cons of each. Which will you choose?
Wood: Wood is probably the most common and least expensive option, and a good candidate for the relatively experienced DIYer. This is also great option if you want a more traditional look. Use rot-resistant woods like cedar, redwood, or yew — and avoid pressure-treated woods that risk leaching arsenic into the soil. Composite wood made from recycled wood shavings and plastic resins are another option, but it can double the cost of the project.
Tip: Rot-resistant wood lasts 10 – 20 years before needing to be replaced, while composite wood, in theory, lasts a lifetime without rotting or warping.
Cinderblock: This is another inexpensive choice, with cinderblock easy to locate and stack. While you can mortar them if desired, it’s just as easy to simply stack them, using a brick pattern for stability. I think this adds a cool “industrial chic” look to your garden, and you won’t have to hire the labor out unless your back disagrees with me.
Tip: Use new cinderblocks, as old ones may have fly ash residue that is incompatible with using in a food garden.
Mortared stone: Mortared stone — whether it’s cut rock or more organically-shaped natural rock — is a more permanent choice that adds a bit of formality to the garden. But it’s not necessarily an easy DIY project unless you’re familiar with the technique, and the labor to hire certainly adds to the bottom line. For our beds, we used 6” blocks of cut limestone and built them approximately 18” high.
Tip: Mortared stone walls need “weep holes” to allow water to thoroughly drain out.
Steel: While not the most common nor the least expensive choice, steel is becoming increasingly popular for raised bed construction. We’ve used a 3/16” hot rolled steel to create raised beds that offer a very sophisticated and modern look — but be aware, this is not a DIY project. You’ll have to locate a steel fabricator in your area and be prepared to dig a little deeper into your bank account.
Tip: Steel heats up quickly and can “burn” any plants that are too close to the edge of the raised bed.
By: Jenny Peterson