This past spring/summer was my first time growing a garden I've learned a lot
And 1 of the things I've learned is I need a bigger garden
I built a 4'x4'x1' raised bed out of untreated wood by the end of year I see I'm only going to get a few years out of it
So if im going to make a bigger garden I need longevity
I've looked at metal ones and I'm not really impressed they're ok if I have to use them
But what I really want is wooden ones cedar is nice but expensive
This bring me to my question whats your experience and thoughts on treated lumber
I've seen good amount of videos and read a few things saying its safe but up until the end I'm on board then they say if you want to be certified organic you cant use it followed by if thats ok and you do use it wear gloves and a mask when handling and cutting
by Fun-Dog-8441
12 Comments
I’ve used untreated pine to build all of my raised beds. They’re 3 years old and still in great shape. Although I know they will eventually begin to decompose.
My first year growing vegetables we got the Greenes Fences cedar kit from HD or something. This was in spring 2020. Very affordable and lasted longer than I thought. We still have one 4×8 that will probably make through one more season with some diy reinforcements. We replaced the other one earlier this spring. So 6-7 seasons is not bad in my book.
This was my first year too, and I want to expand next year.
I thought about buying some cinder block things and fence posts from a home improvement store. That would be cheaper than buying raised beds.
But I’m taking what’s probably a gamble and plan to expand by planting directly in the ground instead of using raised beds. I don’t want to pay for the topsoil/compost to fill beds. I put down cardboard and a lot of wood chips (free from Chip Drop) over the area I want to use next year. Fingers crossed that the soil will be in good shape for planting next year. Don’t know if your soil could be cooperative with direct planting, but just throwing it out there as potentially an easier DIY option.
I’m on team “use treated lumber” based on the chemistry and costs involved relative to the alternatives. Yes, pure cedar would be the superior option if you want to be maximally safe, but that’s a very costly option that still won’t last as long as treated lumber.
The major preservative in treated lumber post-2004 is copper azole. Actual studies on the potential for copper leakage from treated lumber suggest that the risk is extremely minor and limited to about 1″ penetration into the soil around the wood perimeter. [See this OSU study summary for an example](https://extension.oregonstate.edu/gardening/soil-compost/pressure-treated-wood-raised-bed-construction-willamette-valley). Copper is naturally occurring in most soils and isn’t a risk at low concentrations.
That said, yes, you absolutely should wear a respirator when cutting treated lumber (or any lumber; sawdust isn’t great for the lungs in general, and even untreated lumber is exposed to a lot of chemicals during the process of cutting, shipping, and storage).
Ditch the beds and grow in the ground.
I absolutely love my grow-bag-beds. I’ve got 4 of the 8ftx4ft divided beds. Along with several other 5 gallon, 7 gallon, 10 gallon, 4ftx4ft, 2ftx4ft. They’re very inexpensive, movable and I can grow just about anything in them. I even took the bottom out of one for growing carrots.
I would argue that its easiest to just grow in the ground. That said, if your soil is no good then raised beds make more sense (not that you can’t build up your ground soil). Just don’t be surprised when after a year or two you want even more space! At least that’s what happened to me haha.
I was dead set on setting up raised beds this year but didn’t end up having enough time/mental space to get them set up in time, so I just grew in ground. I’m so glad I did bc it seemed to be so much easier!! And I can modify this year!! And also most importantly, I barely had to water most of the summer until our dry spell at the end. Just grow in the ground!!
There’s nothing wrong with using treated lumber. I’ve used it over 25 years, had plant tissue tests done 3 different times over the first 12 years of use with no issues regarding chemical leeching. IMO you’re looking for trouble that isn’t there. The soil acts as a buffer and an insulator. If you don’t want to use metal beds, the only other option is using cedar. There are several members of my gardening group who made beds using cedar fence pickets sealed with mineral oil. They last no more than 8 years, so if you don’t mind changing the beds out you could use this option.
I went to a small mill and bought true 2×6 cedar boards for my beds. Half ad cheap as the pre-made 1 inch thick beds on Marketplace and they look really nice. I do wish I’d treated all the boards with raw linseed oil, but I’d do it again in a heartbeat.
How’s the ground? It has the best longevity, you can actually make it better with time. It’s not that long ago it was the default option, still is where I live
I use 2x12x12 pressure treated for ground contact. 4×12 beds with no problems. Lasts for over 15 years and counting. Have to use raised beds because of poor soil. I started 15 years ago with 2 tomato plants. Now I have 8 beds that do very well.