Is treated lumber safe for building raised bed vegetable gardens?

The following post is from 2013 – but since it’s nearing planting time everywhere in the U.S. I thought now would be a good time to repost it.

After posting a photo of my new raised bed garden frames in last weeks “what did you do to prep this week” post, I received several emails from readers asking if I had built my frames using treated lumber and they then proceeded to inform me of the health risks involved with  the use of treated wood in my garden.

One readers email gave a dire warning to the effect that I would surely die from the first bite of produce taken from the garden if treated lumber was used to construct the frames because arsenic would leach into the surrounding soil and into my food, then kill me when I ate it…

I would like to thank you for your concern, it is appreciated and noted. And to answer the question, yes, my new raised garden bed frames were built using treated lumber but I’m not concerned about it… not even a little bit.

Years ago many folks including several national magazines and agencies suggested that it was “possible” for small amounts of chemicals to leach into the soil from treated wood when that wood was used to build frames for a raised bed vegetable garden. The main health worry was arsenic because treated lumber at the time contained arsenic that was used in the treating process.

According to this article from University of Missouri Extension Office:

“Pressure-treated lumber uses CCA (chromated copper arsenate) or ACA (ammoniacal copper arsenate) as a preservative. However, studies done by Texas A&M Agricultural Extension Service showed insignificant movement of these compounds into surrounding soil. Pressure-treated lumber has no proven effect on plant growth or food safety.”

But, this is all a moot point because arsenic has not been used to treat lumber for residential use (with the exception of some woods for marine purposes) since December 31 2003.

So the admittedly small risk, associated with using treated wood before that date to construct raised vegetable garden beds and frames have been further removed with the elimination of  arsenic in the treating process.

According to Becky Wern, Master Gardener with the Duvall County Agricultural Extension Service and the University of Florida:

Today’s pressure treated lumber “is safe to use around children and animals and for gardens with edibles.”

Also according to The National Gardening Association:

There\’s still a lot of controvery about using treated wood for vegetable gardens. There was a time when pressure treated lumber contained arsenic (CCA) and was not considered safe for use in raised vegetable gardens because the arsenic leached out into the soil. The newest method for treating wood is Micronized Copper Quaternary (MCQ).

It is chemically different than the old CCA treatments. It is made of tiny (micro) particles of copper. These particles are forced into the wood cells or pores during the pressure cycle. Once in, they stay in, also forming a barrier keeping in the quaternary. The leaching of chemicals out of MCQ is practically non-existent and using the treated lumber for a vegetable bed is safe because the chemicals do not leach out into the soil.

However if you’re still worried then don’t use treated wood to frame your raised vegetable gardens, it’s that simple. Or line the inside with heavy plastic (but then I’m sure some will worry about the plastic “leaching” stuff  into the soil) or line the sides with rock or some other material.

About M.D. Creekmore

M.D. Creekmore is the owner and editor of TheSurvivalistBlog.net. He is the author of four prepper related books and is regarded as one of the nations top survival and emergency preparedness experts. Read more about him here.

Comments

  1. Thank you for this article. I was still laboring under the delusion that treated lumber still contained arsenic. I learned something new today.

  2. Chicken Farmer says:

    Thanks for the update on pressure treated lumber. I was also under the impression that hazardous chemicals could leach into the soil and cause health risks. I wonder how those risks compare with some of the foods in the grocery store that are grown in foreign countries under questionable conditions? One may never know. CF

  3. Thanks, MD, for your research on this. We too have used treated lumber for a raised bed.

  4. Before I retired recently I was a dock master for a very large marina on a bay. For yrs we were not allowed to use treated lumber because during rain storms chemicals would leach out into the water, about the yr 2000 or so we were informed by the treating companies that a university in California developed a new process that doesn’t allow for leaching and under the clean water act it was allowed over water that was fish bearing, so I would say any of the newer pressure treated lumber would be suitable to use for garden beds. My two cents worth.

  5. Exile1981 says:

    Now I agree with what you said but you do need to be careful if you buy old used rail ties as those are treated with Creosote and that is listed as dangerous to plants and it does leach out. So a raised bed made with those will likely not produce healthy plants

    • Red Tower says:

      Actually, plants can be quite healthy in RR tie beds–however, you are right about the creosote leeching out. My MIL uses hers to plant the flowers and pretty things in. These, in turn, distract onlookers from her food garden in back.

  6. Unfortunately it does not seem to matter what material a raised bed is made from up here, except for a few flowers, I know of no one who has gotten them to work. I think the ground, when raised, just stays too cold.

    • Red Tower says:

      We have some in our yard in WY. You may be right about the ground being too cold. We don’t usually put our plants out til June, keep them in the greenhouse or house til then. Our beds work better because the soil in our yard is lousy. There were two other houses on the property years back, and they put fill dirt over the whole area. PH is TOO basic. Coming around though, slowly.

  7. I have never used treated lumber… wood of any sort is a do-over. I built my current beds out of concrete blocks, which leaches lime. Most vegetables like lime. I will say that my beds stay pretty balanced because the deadwood can be acidic. My favorite beds are built of field stone. I pick up “free” stone and their is a labor cost… less because I use a small collapsible utility truck.
    I worked in IP law with nanoparticle researchers. Nanoparticles are not safe and there is independent research showing that… Nanoparticles are used to change the weather.

    • I too figured wood would eventually rot, which was why I put 2 coats of ext polyurethane on the treated wood I used for a raised bed, & after 5 yrs it’s still in good condition. However, I like the idea of using concrete blocks & am going to google that. Can u describe how u used the concrete blocks or link a good article showing how?

      • RedC
        I am still building beds for spring… www dot treeseeddreaming dot Com has my photographs. Mine are also hugelkultur beds, using deadwood in the bottom to soak up water like a sponge.

  8. Jersey Drifter says:

    I bought pressure treated lumber for my raised beds. The lumber mill’s tag that was stapled to the end of each 2 x 12 gave info as well as the company’s name. A little research on their web site as well as Government and independent sites convinced me that any danger was very, very minimal. I have to agree with M.D., todays lumber won’t cause you harm like the old stuff used to.

  9. I simply lined the interior side of my raised beds with 6 mil plastic. This keeps soil and water from coming into direct contact with my treated wood material and will keep it from rotting out. No worries about toxic leaching either.

  10. mom of three says:

    Going outside and having the fake rain, coming down is just as bad. I use filter’s in my refrigerator, and a filter containers to get city water. The aluminum and barium, they spray is awful what is it doing to the plant’s and tree’s, it killing them in our area dead bushes, tree’s, I have no idea if the neighbors Japanese Maple tree will even come back this year, since they started spraying a few year’s back plant life is slowly dying around us. I can’t believe how much I’ve been getting sick and it’s not all allergies either so until they stop spaying really I’m not going to worry to much about treated wood.

    • Now that is sweet! I don’t use chemically treated anything, either. At some point just getting food to grow is important.

    • Most plants are fully capable of diverting Aluminum. Barium I will do research on. Humans cannot deal with Aluminum. It can be easily removed with a chelation. By doctor or food. Ask your doctor for a test to see if you are one of 80 percent of Americans with toxic levels of Aluminum. Barium is bad stuff… more to research…

  11. cgbascom says:

    To my family, friends, and neighbors. I humbly beg your forgiveness for my rotten attitude toward your raised garden efforts using pressured treated wood. My you always have big tomatoes, sweetest tasting peppers, and beautiful broccoli. I, on the other hand, will crawl back into the hole from which I came and will speak no more evil.

    • egbascom, I didn’t see your original comment or email that led to this one, but I don’t think u should feel too badly. We’re all here to learn. MD & other experienced preppers have a lot to teach us. I suspect we’ve all changed our minds on some things after learning more about it. So I hope u feel free to come out of your hole & post more questions or comments.

      • cgbascom says:

        RedC rest assured, that with my big mouth I will not be able to resist spewing forth, again. I use cement blocks in my raised gardens. They help keep the soil warmer, and I get little extra places to plant my leftovers. Since I live in the UP, the extra warmth is necessary and welcomed. I have been a member of the Wolf Pack for almost a year. I have learned a lot. And look forward each day to this blog. Thanks for your concern.

  12. People can start dating the change in PT formulas when they also had to change the type of screws they had to use. Older screws, made for the arsenic formula wood did not ‘agree’ with the new formula and began rotting out quickly. Now your lumber store will steer you to the correct screws because there’s still plenty around of the old arsenic type.

  13. Chuck Findlay says:

    I do handyman / construction work, and run across old treated wood a few times every year. There is a somewhat popular movement to re-use old wood, windows and metal roofing and some of the old wood ha the bad stuff.

    I’m not sure how to tell good from bad?

    My dad got very sick for a few days about 15-years ago when we were cutting a bunch of treated wood for a deck.

    Be careful with the old wood if you reuse it like some of my customers do.

  14. Think cinder blocks….

  15. I am of the opinion that most consumer goods developed in the past hundred years or so are poisoning the population. I am 69 years old, live in Oklahoma, am a cancer survivor, had a brain tumor removed, and am still kicking – kind of. My point is that I was a child downwind of the atomic tests conducted in New Mexico during the 40’s & 50’s. I can’t tell you how many spawn of my generation in this area of the country that have developed cancer &/or brain tumors. Likewise, I don’t remember anything about attention disorders in children back then. We had it, but it was classified as being unruly children (usually boys), that hasn’t changed. I do think we are poisoning ourselves by cooking & eating products from aluminum & plastics, non-organic meats, and too much carcinogenic products in the environment. As for treated wood for raised beds, which I have done in the past, I do not believe it to be good for plants, people, or even dirt. If it was truly safe to come into contact with, why are we warned to wear thick gloves when handling it when it is wet? There is so much misinformation out there on any possible subject it is extremely confusing and boggles the mind. Personally, I steer clear of cooking in aluminum, storing foods in plastic instead of glass, and prefer raised beds made of metal or concrete, or even rock. But, I will never give up my coffee (in a steel or ceramic mug, made in steel &/or glass coffee maker, beer in glass bottles, and most importantly, BACON! I don’t expect this will be posted, my comments never seem to make the cut.

    • Nanook,

      What comment of yours has never been posted? I don’t remember ever sending one to the trash.

      • M.D. Actually, there has been a few. I once commented on surplus military equipment, sleeping bags, ruck sacks, etc. Never made the cut. That is the only one I recall, off hand. Another of your posts I wanted to comment on is UTV’s/ATV’s. Now, bear with me on this because I do have some experience/knowledge. Back in ’08, my knee that has had 6 surgeries on it over time finally gave out. It was to the point I could not walk up or down hills or stairs without considerable pain. It hurt so bad I could no longer ride my horse. An avid outdoorsman (though a little on the lazy side), I was at Bass Pro, and on impulse bought an ATV. Why, you ask, would I do that? I have no good answer….but I did. I’ve had it for 8 years & I doubt it has 1000 miles on it, though it is fun to ride (I now have a new knee). I’ve been a Jeep man since I was a teen. I didn’t have one at the time I bought the ATV, but was looking for a good one. After I bought the ATV, I’ve kicked myself numerous times for not getting a UTV. But, being a Jeep man, a UTV would be overkill. It can’t be legally used on the roads & neither can a ATV, but a Jeep can. Plus, a Jeep can go & do everything a UTV can do, just better. I can not think of a single use for a UTV that justifies the expense vs a Jeep.

      • Oh yeah, I should add that I really like and appreciate this website. I have pretty much shied away from all the others, except Dr. Bones & Nurse Amy’s, unless it has to do with guns…LOL

    • Nanook. I agree with you. Everything is pretty much toxic and after living in this country 62 years I no longer believe anything the government or their corporate masters say about poisoning us. Every now and again they admit to one… but but but everything else is okay. No kidding?

      • Rebecca, just research how aspartame became legal to use that will show you how our FDA works, if they say it’s harmless it means somebody got paid off.

        • WxNW
          I am not sure my little heart can take that one… but okay, I will go look. To take credit I do not use Aspartame or any other artificial sweeteners. Or fake butter, either. I try. I save seeds and cook from scratch. I increased my garden area this year.

        • WxNW
          I knew my heart couldn’t take it. Sidley Austin, Searles’ law firm, offered the lead investigator, Skinner, a job in the middle, and it delayed the case past the statute of limitations. I didn’t work there when it happened, but working there and the other big law firms killed my faith in corporations and corporate-owned government. My heart is still broken.

          • rebecca,
            if we knew all, our hearts would all be broken and we might actually die in floods of tears.
            i am glad that i am not a lawyer or a politician, or any other sort of corruptible in a place of responsibility.
            at my age i know there is no trusting anyone especially in government.
            but be of good cheer, this too shall come to an end.
            we all just do the best we can.
            i love this website, so much knowledge and experience to choose from.
            keep your chin up.

            • Wasp,
              Kind of you, thanks.
              I wasn’t directly involved, more a witness of how it worked, and had to work so hard that it took me a while to get it.
              But yes, it breaks the heart.
              What I am left with is my 5 acres, my garden, and my puppydog. My son and grands are a long ways off.
              It is a satisfying life, more than the one I walked away from.
              I would sell here and live closer to my family if I can manage it… but this is a beautiful property, for sure.

        • and oleo.

          • Oleo is not food. Neither is genetically modified rape seed oil aka Canola. I am working on my garden and producing my own oils. Meantime, I buy Italian olive oil.

    • U made the cut my friend and Rock on! ..like u say..u r still kicking !!;)

  16. I got pressure treated around the 8 by 24 but the 2 4 by 4s are made from cedar.

  17. As someone that owns a small farm I can’t be certified “organic” if I use pressure treated wood anywhere near where food is being grown, animals grazed, ect.

    If you don’t care about the label “organic”, like me, than use pt wood. This article in Fine Gardening is very good if you still have doubts. http://www.finegardening.com/are-pressure-treated-woods-safe-garden-beds

  18. Considering what I’ve read today about treated wood, etc. I am questioning sawing plastic sewer pipe in half lengthwise and use it for a raised bed. Any comments?

    • Bob
      it would work, certainly. Plastics release toxins, don’t they? I don’t know exactly what type of plastic sewer pipes are made from, certainly not food grade. I have seen people use water troughs. Free pipes would be tempting, but I wouldn’t buy any. Would you slice pieces off and have a lot of circles, or slice lengthwise and seal the ends?

  19. How about sawing discarded plastic sewer pipe in half lengthwise and use it for raised beds?

  20. Bob
    it would work, certainly. Plastics release toxins, don’t they? I don’t know exactly what type of plastic sewer pipes are made from, certainly not food grade. I have seen people use water troughs. Free pipes would be tempting, but I wouldn’t buy any. Would you slice pieces off and have a lot of circles, or slice lengthwise and seal the ends?

  21. Irish Yoga says:

    I was a foreman at a treating plant way back in the mid 1980’s when they were using CCA (chromated copper arsenate). I was exposed to the liquid chemical on many occasions on my bare skin. We had to have a urine test every 6 months to check arsenic levels. Not once was I ever over or near the limit in several years. The actual concentration of the chemicals in the liquid back then was only around 2.5 percent.

    Ironically, many guys from the east coast who worked at the plant and ate a lot of seafood (which contains arsenic!) had to stop eating any seafood 3 weeks before testing so as not to skew the urinalysis readings.

    As for treated wood itself, it is one of the biggest scams I’ve ever seen. Most of the lumber is merely skim coated with chemical (despite it being subjected to fluctuating high pressures in an autoclave) because it does not penetrate the dense heartwood, which is very hard and dense compared to the outer softwood on a tree. Small diameter trees have little softwood and when sawn into smaller 2×4’s and 2×6’s most of the boards have little or no softwood. Southern Yellow Pine is one exception since it grows like a weed and the fibers are very porous. It’s also very heavy after treating since it soaks up so much chemical.

    Our resident “wood scientist” at the plant even thought it was a scam. He told me the average lifespan of untreated wood was about 14 years, and back in those days the so-called “30 year warranty” on the wood was not transferable to a new homeowner that buys your house with your recently installed treated lumber deck in the back.

    If you want treated wood it’s cheaper to buy raw lumber and a gallon of the brush on chemical and paint it yourself since you’ll get about the same penetration with the brush as you would with a fancy high pressure autoclave. And since wood will split and crack, exposing the untreated wood beneath, at least you can fill in those gaps with your left over pail of brush on wood treatment.

    I have never bought treated wood (for myself) since the 80’s. The only exception is 4×4 post lumber. It can be tough to find a lumber yard that has untreated 4×4’s unless they cater to a more industrial clientele.

    Sorry for the long rant, folks. I could carry on with many more examples but I’ve probably bored y’all by now.

    Cheers!

  22. I built 6 raised beds with treated lumber over 10 years ago and have suffered no issues from it. As for the rail road ties, I use those for flower beds only.

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