Types of Wood to Use For Your Garden Beds

The materials you use, including the type of wood, is just as important as the soil, and eventually, the plants.How much do you know about wood? I know it’s great for painting, but different types of wood can make all the difference in how your beds turn out, and how long they last. So let’s dive in right now.

I asked John today about what kind of wood he purchased to assemble our beds – as in what type of trees.. That’s one thing I didn’t remember – my biggest recollection was bringing in all the lumber planks one by one, through the front door and making sure not to hit anything on the way to the backyard.

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I wore gloves so I wouldn’t get splinters in my hands. He didn’t think it was all from one type of tree – oak, pine, and spruce where what he recalled. Let’s take a look at all those kinds of trees and their respective wood, and how well do they fare in our beds.

But first…let’s talk about what NOT to use, which is just as important, too.

Pre-Treated Wood: Good or Bad Idea?

The most important thing to steer clear of is wood that was treated with CCA which stands for chromated copper arsenate. This is a substance that was deemed toxic outside of industrial use and banned by the EPA about 20 years ago. Even with that, it’s important to do your homework first.

Reclaimed railroad ties which are treated with creosote, are an example of a no bueno. In fact, I was under the impression it may actually be unlawful to use them residentially since creosote (a preservative used back in the day as a fungicide/ pesticide) has been declared a carcinogen. I take that back – it’s acquisition and disposal of them unlawfully that could get you in hot water. Don’t quote me 100% here – you may want to do some research on the rules where you live – More info here

Even though they have that distressed rustic look which appeals to many landscapers and gardeners, I’d leave them be, or save them for other outdoor projects. Wood treated in this manner, could leach toxic materials into the soil (and thus, the plants) which could mean that it’s probably not safe for your eventual vegetable food crop!

CCA has since been replaced by a more up to date treatment method known as ACQ (Alkaline Copper Quaternary).

So if you are interested in a particular batch of wood, be sure if it has been treated, it was with ACQ or another similar one, Copper Azole.

Look for Rot Resistant Wood Types

Some species of common trees are hardier and more resistant to disease, pests (e.g. termites), or degradation more than others. The most rot-resistant types of wood comes from these trees:

Cedar, Pine, Douglas Fir, Spruce, Redwood, Cypress, Hemlock, Chestnut, and Juniper.

What you may find available can depend on your region. Where I’m from, pine is super abundant. If you live on the west coast the redwoods would be great to look into – they have super good longevity, only second to cedar.

Cedar and redwood’s longevity is about 10 years. Pine is closer to about 5 years. Whether this (average/estimated) amount is important to you will depend on some things. If you are renting a place or unsure of how long you will be putting down roots for the long term, this may not be as important.

Save those tree limbs that are not rot resistant to use as part of the layers for building up the soil in your beds instead.

When you do go shopping for wood, one thing to use in the process of evaluation, check and see if the lumber company you’re dealing with has been certified by the FSC. (Forest Stewardship Council – a nonprofit organization dedicated to sustainable and environmentally sound practices with wood).

When you assemble your beds, you also have the option of using a non toxic sealer to preserve the integrity of the structure. We didn’t do that – we used small stakes cut to the height of the beds in each corner and halfway through the middle of each 2 x 4, to add more stability. If you don’t have heavy precipitation to begin with you might be better off doing what we did.

Hopefully this post has given you some ideas for how to find and source wood that is free from toxic preservation methods and not too expensive, either (hopefully). Good luck to you!