You’ve got perfect soil, a level yard, consistent rainfall, and everything grows beautifully, right?
Every garden has challenges and raised beds can resolve many of them.
But what kind of wood should you use? Are some types of wood harmful for the garden?
Here’s what you need to know.
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Wood Raised Beds
There’s plenty of obstacles to creating a great garden. Slopes cause erosion. Bad soil is expensive to amend. Tree roots prohibit digging. Plus, knee and back problems can make it difficult to get in the garden (or get back up!).
Raised beds can solve all of these problems and more. Wood is a popular choice for building plant boxes because it’s fairly inexpensive, readily available, and lasts quite a few years. But you do have to choose carefully to avoid contaminating the soil and find an eco-friendly source.
What I Use in My Garden
- I now use 1″ pine boards because they are readily available in my area. The wood gets a lovely, rustic barn board patina after just one season.
Raised Bed Revolution by Tara Nolan
What is the best wood for raised garden beds?
For me, locally-sourced, FSC-certified, untreated wood makes the most sense.
Keep in mind that wood selections vary greatly by region. I admit the suggestions (below) are quite idealistic, but why not do what’s best for the health of your garden and the environment if you can?
Local & Sustainable
- The best choice (and often the lowest cost) is locally-sourced wood, coming from sustainably-managed tree farms (as opposed to decimating old-growth forest by clear-cutting).
- If you can, use wood with FSC (Forest Stewardship Council) certification. The FSC is an international, not for-profit organization that promotes the responsible management of forests.
- Do not use the older CCA (Chromated copper arsenate) pressure-treated wood or old railway ties. The chemical preservatives can migrate into both the soil and plants. As thrifty gardeners, we like to repurpose wood that seems to be in good condition, but this is not an option with old, treated wood. Get lumber you know is okay for your food garden and does not negatively affect the soil.
- ACQ: Alkaline Copper Quaternary treated lumber is a more recent improvement. If you want to use this stuff, be sure to do your homework first so you’re certain it’s safe for your food garden: not just fence posts and decks. Also, safety standards may vary by country or region. What goes in your soil goes in the water, plants, and wildlife, so it’s important to be careful.
- How long any wood lasts will depend entirely on the type of wood and local conditions. My current raised beds are made from 1″ untreated pine and last approximately 10 years. But I also live somewhere where the rain is moderate and the drainage is very good.
If your raised beds will be exposed to a lot of moisture, wood like pine may only last a few years.
- Other naturally rot-resistant woods (listed below) will last even longer.
Types of Wood
Here’s a few popular ones:
- Naturally rot-resistant, long-lasting
Cedar, yew, redwood, juniper (has a very rustic look)
- Dense woods
Black walnut, white oak, locust wood
- Other Options
Spruce, pine, Douglas fir
- Recycled or reclaimed wood if you do not know the origin or wood that has been stained or painted.
- Older (CCA) pressure-treated wood, which is banned in several countries. ACQ (Alkaline Copper Quaternary) lumber is a better alternative.
Do your research first to confirm you are comfortable with the exact product you are using.
Wood Alternatives for Building Raised Beds
As with any building materials, you must do your own research to make sure the choices you make are safe, eco-friendly, sustainable, and right for your situation.
These are ideas to explore, not recommendations.
- Recycled composite plastic lumber
- Composite lumber—made from recycled wood shavings.
- Cinderblocks or bricks—can get quite hot in the sun. Do your research first: these materials may negatively affect soil quality.
- Metal stock tanks —can rust over time.
- Galvanized culvert or stock tank—may heat the soil too much.
- Steel – not sure if this is food safe.
- Felled logs
- Old doors—cut lengthwise – be cautious with any paints or stains.
- Shutters—be cautious with any paints or stains.
- Straw bales
- Railway ties—creosote-soaked ones are not safe.
- Tires—I know this is fairly popular but I am not convinced it is a soil-safe idea.
- Paints, stains, finishes—you don’t want them leeching into the soil. And watch out for old, lead-based paints.
Free Plans for Building Raised Garden Beds
- Free Plans for Building Raised Garden Beds
- Also check your local library or Amazon.com for books like these ones.
Good luck with your raised beds! Now go grow something wonderful.
~Melissa the Empress of Dirt ♛