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Used railroad ties to create raised garden/what to do now?

May 6, 2012

I paid my gardner to use railroad ties to create a raised area with the plan of screening it off so I could create a garden that the critters would not be able to get to. I was just informed that railroad ties are very toxic/carcinogenic.

I'm going to remove the ties, however, my concern now is that whatever comes off of the ties may have already leached into the soil. Any idea how much soil I would have to replace to make sure there is no danger from what may have already come into the soil?


Comments (36)

  • digdirt2

    Your choice of course but many gardeners have used old railroad ties to create their gardens with no problems. How much creosote remains in the ties all depends on how old they are. How much actual 'leaching' they may or may not do is highly debated and how much may have leached, if any, all depends on how long they have been in place as the weather/moisture/heat they have been exposed to.

    In the past, the standard recommendation when using treated wood products was for a 4 foot DMZ. But that was for the arsenic that used to be used and I don't know if it needs to be that size for railroad ties.

    It basically boils down to your choice.


  • Joe1980

    People have been using railroad ties for gardens for ages. It depends who you talk to about how "toxic" they actually are. I suppose if they were brand new, they wouldn't have aged and/or leached anything yet, but if they are used, they've leached off any fresh chemicals over the years, and don't have much left to give. All in all, it depends on how YOU feel, but personally, I don't find an issue with it. Is there better options? Sure, like the supertoxic treated timbers I used. The most dangerous part will be when you drive somewhere to dispose of them. Or, when you don't have time for a home cooked meal, and you eat a toxic, preservative packed frozen pizza or TV dinner. We won't even talk about toxic fast food....


  • RpR_

    I havd railroad ties bordering my garden now and when they need replacement I will put different ones in.

    I would put the "danger" of railroad ties item up there with other Chicken-Little schemes the "professionals" concoct to hear themselves speak while getting government money for their "study".

  • nygardener

    I'd call your county's cooperative extension and get your soil tested. It's easy and cheap and then you'll know.

  • jolj

    I used them years ago, have a co-worker who still use them in his garden.I do not use them now to be safe.
    But some persons think anything man made is bad & talk of pure this or that.
    It is said that one should not use peat moss, peat moss is now bad.
    So you need to make up your on mind, you could grow in the raised bed as is & have the fruit tested for toxins.

  • bellbound

    1.) How would I test the soil for toxins?

    2.) How would I test vegetables for toxins?

    Thanks everyone!

  • digdirt2

    1.) How would I test the soil for toxins?

    You would have to have a professional soil test done and they routinely do not test for any toxins or contaminates. You have to pay extra for it.

    2.) How would I test vegetables for toxins?

    Again that would be done by a professional lab, one that specializes in that sort of testing.

    So consider these points:

    1. Do you eat store bought food? If so do you have it tested first? Of course not. Like all of us your wash it well before consuming. Contaminants, if they exist, are on the exterior of the food.

    2. Are you aware of the many chemicals that lab testing has already shown are present on many commercially grown foods? Do those test results keep you from eating that store-bought food? Of course not.

    3. Why do you assume that your soil didn't already contain other contaminants from long before the railroad ties were installed or that it is already contaminated by the railroad ties? Why assume that any home grown food grown there would be even more contaminated than store bought? Contaminated with what?

    4. If we assume for purposes of discussion that your soil already contains some contaminants - most soil does contain some - why do you assume the food would absorb it internally? Plants have a very well developed filtration system that is totally water-dependent. Only water soluble contaminants of very specific particle size could even possibly be absorbed and the odds of that is very slim indeed unless the ground were so toxic that nothing would grow in it in the first place.

    With all respect I think you have read one or two questionable sources of info that have scared you into way over-reacting. Perhaps you need to reconsider the whole process of gardening. It is often a dirty, buggy, disease-fighting process and it isn't for everyone.


  • Joe1980

    Dave hit it right on the head. If I were you, I would commence planting. Also, take with a grain of salt, the information you read on the internet. There are a lot of "experts" out there, who, thanks to the internet, now have a place to share their "facts". Some are right, some are wrong. It's up to you to make a decision for yourself though. Just remember, people, including myself, will always defend their "ways", including how they build their garden and why. Jolj also makes a great point in that some people think ALL manmade stuff is bad; that's their story and they're stickin to it.


  • lonmower

    Several years ago I watched a friend build his vegetable garden from used railroad ties. He was well into the project when I first saw it and I held my tongue. I would never use URT's myself, but I wasn't about to put some kind of heavy (organic) trip on him. Who really knows if they are bad...but they are made by soaking wood in some fairly toxic substances.

    All that said...to me, for your own peace of mind...I would rip out the URT's and replace them with 2 by cedar or redwood. The cost will be replaced by the knowledge that you might be doing the right thing. I would not replace the soil in the whole bed. If you take out the URT's...the soil around the edges will fall away and can be used to build new flower beds.

    Those that tell you that "store bought food might have toxins" are in my opinion "stupid people". If store bought food has toxins...and you eat it...you might as well just invite "Death and Disease to Dinner"

    If you make a mistake...fix it by doing the right thing.

    PS...I am NOT a "tree hugger" or organic crusader!

  • digdirt2

    Those that tell you that "store bought food might have toxins" are in my opinion "stupid people".

    So sorry to have offended you with my stupidity lonmower. But I have to ask, what planet have you been living on if you are unaware of the issues associated with contaminants in commercially grown and processed food?

    And I'm not a tree hugger of organic crusader either.


  • howelbama

    Check out this article on using PT for gardens, dispels a lot of the fears... Most of the risk is in touching the wood, not so much in the soil or growing in it. Good scientific info from credible sources...


  • lonmower


    My point about toxins is...if one goes to the grocery store and thinks that the non organic produce has toxins and buys them when organic produce is available...that is stupid. Many people do not think about toxins in non organic produce. Toxins are NOT an issue with them. Not on their radar.

    Bellbound is now aware that her URT's might be a potential health risk. One can not put a price on "peace of mind"...that is why I recommended to pull them out. If I moved to a property that had URT's as the border in raised beds, I would do whatever necessary to grow veges in a new or different environment.

  • homertherat

    I grew veggies in a raised bed made from railroad ties for 15 years. We werent poisoned. I'd do it again in a heartbeat if I didn't have so much land to work with now. 8000 sq feet is plenty.

  • lonmower


    You obviously don't think there are toxic carcinogens leaching from URT's. Fine!

    I personally don't know if there are or not. I do know that they have been soaked in toxic substances. Given the choice...I would err on the side of safety. That was my advice to Bellbound. In an era when the cancer rates and general use of herbicides and pesticides and petrol-chemical fertilizers (and URT's) have dramatically increased...seems to make a body wonder about things(?)

  • toxcrusadr

    A few facts...

    Pressure treated wood does not equal RR ties. RR ties are made with creosote, derived from coal tar, dissolved in diesel fuel as a carrier. Creosote contains probably a couple of hundred hydrocarbons and phenols, some of which are known to be carcinogenic.

    Having said that, "the dose makes the poison". Used ties will have given up much of what was on/near their surfaces over the years. Factor in the volume of soil, actual plant uptake, and, well, this env. chemist isn't too worried about it.

    And yes, there are tiny but measurable and 'acceptable' levels pesticides in food from the grocery store. There are a host of similar, non-zero environmental risk factors.

  • homertherat


    It was much cheaper and easier to get 8 railroad ties to square out the raised garden bed than it would have been to get lumber, screw it together, treat it with some type of oil, and then have to be careful with any kind of equipment around the garden. I ran into the "URT"'s many times with the lawn mower, tiller, gas trimmer, etc. and it barely left a scratch. The regular lumber would have been mangled.
    There may have been leaching of some sort into the soil, but i haven't seen any negative effects. I just know it was cheap and it was easy to set up. I don't think that enough could leach off, travel through the soil a foot or so to the nearest plant, and then get soaked up through the roots and distributed into the fruit. Trace amounts, sure. But after years of rain and sun beating down on them, most of it had probably already leached out.

  • oregonwoodsmoke

    Keep the beds. You've already paid for them. Plant them with beautiful flowers.

    Put some raised beds for your veggies on the other side of the yard.

    In fact, if you like to barter, fill the raised beds with named irises. Irises, even the unknown varieties, make great items for barter.

  • nc_crn

    The biggest...and pretty much only...issue with the stuff is direct contact.

    If they're really old to the point of flaking/dusting then things get a little sketchy if you're around it a lot and breathing it in.

    That said, if the wood is in good condition just wash your produce and try to make as little contact with the wood as possible. You don't have to treat it like it's radioactive and hover over it, but try not to get your hands all over it for long periods of time and wash your hands afterwards.

    It's not one-time exposure to the dangerous stuff in the wood that's an issue, it's long-term consistent exposure.

    As far as things leeching into your produce...no issue. Washing your produce is a good practice, though.

  • albert_135   39.17°N 119.76°W 4695ft.

    It would appear there might have been a time when there were two sorts of creosote, one a plant bi-product and the other a coal bi-product. I don't recall reading when persons using creosote as a preservative switched to coal bi-product.

  • mytime

    Albert, I think it was sometime before 1850.

  • sitano

    What if you lined the interior side of the URT with a heavy plastic sheet? Would that direct any leaching outside of the garden box?

  • mckenziek

    Personally I would not trust the railroad ties either, just because the exact treatment is unknown. Obviously from this thread, many other people have not had any noticeable problems with railroad ties.

    If you just installed the railroad ties, then I would not worry about removing soil that has already been in contact with them. Leaching is normally a slow process.

    I didn't follow the link from howelbama with reliable information from credible sources, but that would probably be a good idea if you are considering keeping the ties.

    I am pretty sure that I personally would not have the soil tested for toxins just because the railroad ties touched it for a little while. Anything which washed out of the ties that fast will probably wash away just as fast next time it rains. If you have other reasons to test the soil, well, that is different.


  • seysonn

    Number ONE: If, any harmful chemical ever had been in RRT, it must have leached already over decade of weathering .

    Number TWO: I something is going to still leach, it is going to travel downward NOT SIDE way.

  • ZachS. z5 Platteville, Colorado

    Plant's, basically, pick and chose what substances they take in and what substances they leave out. I'll tell you, I am not worried about a few ppm of creosote from a rail road tie getting into the plant, and neither should you.

    For dissolved molecules (toxic or otherwise) to be transferred from soil through the plant, they have to enter the plant cell structure. First through the root hairs and then travel through a series of checkpoints in the cellular cortex, the epidermis. They can either travel from cell to cell along the cell walls, or they can "break through" the cell walls and membrane and travel via the cytoplasm, it depends on what the molecule is. The plasma membrane of the cell is designed to only allow certain things in, based on their size, structure etc.. So, while a calcium molecule may be able to pass through the cell membrane into the cytoplasm, a creosote molecule may not, thus, the latter would have to travel via the cell walls.

    The final checkpoint is the endodermis which has a band of impermeable substance that neither water nor dissolved molecules can pass through traveling along the cell wall, blocking anything thing taking that route to plant from entering. In order to get into the plant's vascular tissue, the only way in is if you fit the description set by the plasma membrane. If he don't let you in, sorry bud, you're out.

  • mckenziek

    The screening mechanism is not perfect. Some things get through. Heavy metals, for example. I mean, you could say the same thing about humans. Everything absorbed through the gut lining is screened, so in theory, only beneficial things pass. But it is still possible for humans to die from ingesting toxic substances.


  • seysonn

    My point was/is that supposedly an old RRT leaches some chemicals in minute quantity, Where that is going to end up ? The answer logically is to the thin layer of the soil next to the tie and by rain or watering that is going to sink further down by gravity. Unless one plants things between the tie and the soil, there is very negligible near zero chance for the plants to be exposed to it.

  • ZachS. z5 Platteville, Colorado

    I agree with saysonn. you highest concentration of any leeched materials is going to be soil in direct contact with the souce. chances are that even the highest concentration is going to be very negligable. the average ppm of leeched toxins (if any) throughout your entire garden is going to be even lower then that.

    I understand that the check system is not perfect, we can get into isomers and things like that but overall even with that fact I go back to the previous paragraph.

  • WeakStream

    I had to join the site in the interest of stopping the awful casual advice on this subject.
    There are so many quick and often ignorant posts I don't know where to begin, but since I actually do care about the health of people please allow me to get the thread back on the rails (that's the only pun in this post :))

    *Some on here above stated that it wasn't even certain that the TS would have coal tar creosote and might have a plant based on TS's RR ties. -That's wrong, -plant based Creosotes are not used in Railroad Ties generally, and in the times they experimented with them, oil and coal tar were essentially always part of the formula.

    *Someone on here stated that contaminates are only on the exterior of plans/vegetables -This is false -and sad,.... really sad. Creosote has an unbelievable amount of compounds that run the spectrum on chemical structure size -there isn't a plant membrane in the world that is impervious to all the different single molecules and chemical compounds in Creosote. This doesn't mean that every plant will draw up enough of the carcinogens to be dangerous -but unless you have a mass spectrometer in your house (like I did growing up with a Scientist for a Dad) -there's no easy or inexpensive way for you to make a judgment -which is where common sense comes in. -Just avoid RR ties for gardening

    Someone on here said that only the immediate dirt could be in question -False -everywhere downstream of Creosote can be impacted. Any membrane Creosote can diffuse into, or water can carry it, or via the air where the many compounds can be carried onto adjacent plants. Since personal body chemistry, magnitude and type of exposure, and a lot else go into that formula for the likelihood of who get sick or develop cancer you would never really know if you are at high risk until it's too late.

    Someone on here said if the RR ties are old they probably don't have any more leaching to do so don't worry -False again -AS SOON as the tie is exhausted of the majority of Creosote which essentially make it impervious to moisture the timber will rot quickly -If your Railroad tie is even mildly structurally sound it's still kicking out some creosote into the environment.

    Someone on here said the danger of railroad ties was overblown and provided a link to prove it -but the link was not about creosote but rather arsenic in pressure treated lumber. Please don't take advice from someone who is confusing 2 completely different things. -They meant well or were trying to expand the topic -but they also tried to convince TS that there was really no danger.

    People on here using examples of daily toxicities of other things in your life as a way to ignore this one is ridiculous too -If you can easily avoid something carcinogenic or help someone else make better choices why wouldn't you? I flew 130 times last year and opted out for scanning every time at the TSA (Millimeter and Backscatter) -Why? -because I'm already getting a nice dose of radiation on the flight and especially once at altitude -but I do get a choice not to get irradiated at the TSA checkpoint -so I choose not to -I'll save my poisoning myself for the places in my life where the choice cannot be made or knowledge to avoid isn't as easily discernible

    The following statement made above by another keyboard green thumb/medical doctor "I would put the "danger" of railroad ties item up there with other Chicken-Little schemes the "professionals" concoct to hear themselves speak while getting government money for their "study". THIS IS JUST IDIOTIC -The danger of railroad ties in proximity to agriculture is understood enough to make sense to mitigate the risks and avoid exposure. There is not even a question in the scientific community of whether it is a good idea or not to use them around food sources. It's not.

    Now, with that done. Just do not use them -use stone or something inert around your food supply and kids. If you have them already, don't panic -I would swap them out when you can and reapply new soil at least the adjacent places.

    I'm not trying to scare anyone either -just that we are talking about sensible choices here -easy things you can do to help your food have the healthiest overall nourishment for you.

  • JoppaRich

    "I personally don't know if there are or not. I do know that they have been soaked in toxic substances. Given the choice...I would err on the side of safety. "

    If you avoid everything that "might be" dangerous, you basically can't go outside (or stay inside). Everything could be toxic.

    I'd rather err on the side of science.

  • howelbama

    Well, that was a bit condescending.

  • digdirt2

    By all means let's drag up another old thread, rehash it all again, and send the OP more emails he/she was likely tired of getting 2 years ago.

    WeakStream - since you did that what sort of supportive documentation do you have for all these claims you make please?

    For example, in 2008 the Environmental Protection Agency completed a reassessment of this question and published those results. Testing determined that

    1. plant-based creosote has increasingly been used for this purpose since the early 1980's.

    2. that its primary source of potential health risk is to the workers in the wood-treatment plants working with fresh mix but that even that risk is minimized by safe handling,

    3. that creosote can be harmful to plants if it comes into direct contact with them. The substance will also produce vapors in warm weather, and exposure to these vapors may damage plant leaves. Creosote that seeps into the soil may damage roots directly, but plants will not absorb the substance into their root tissue.

    4. that keeping plants at least several inches away from treated timbers usually prevents damage from direct contact and vapors, and creosote will generally not migrate far enough through the soil to reach plants that are a short distance away

    5. short-term exposure to creosote can cause skin, eye and respiratory irritation; longer-term exposure may cause organ damage or cancer. In the garden, you're unlikely to have more than short-term direct contact with creosote, and because plants don't absorb creosote through their roots, you won't be exposed to it by eating vegetables grown near treated timbers.

    I am not claiming this is the definitive position, just that there is supporting evidence that would seem to undermine many of your claims.


    Here is a link that might be useful: US EPA - Resources on Creosote

  • karlaninas


    Creosote is a known carcinogen and should not be used for beds. So says the EPA. Its listed as a hazardous material.

    If nothing else, it will kill all the beneficial micro-organisms in your soil and reduce the nutrition in your food.

    We are exposed to enough carcinogens on a daily basis. Why add to the list?

  • digdirt2

    "If nothing else, it will kill all the beneficial micro-organisms in your soil and reduce the nutrition in your food."

    Proof of or at least supporting documentation for this claim please.


  • karlaninas

    Creosote is widely used as a wood preservative, fungicide, insecticide and herbicide. Our soil needs a healthy balance of micro-organisms, especially bacteria and fungi so that the plant may draw nutrients from the soil and therefore supply us with those nutrients. It stands to reason, that if the creosote affects the soil biology, it would affect the nutritional density of the plants themselves. However, I also read that the plants do not take up the creosote themselves. I agree, there is a lot of varied evidence and experiments, but nowhere has it said, - Creosote is completely harmless!

    Fungi and bacteria will have double duty in that soil. They will attempt to remediate the creosote themselves and do the repair work, but they also are a nutritional network for the rhizome layer on the plants.

    This article is ok but doesn't' have any scientific values, just statements.


    this is an awesome article on soil biology. http://dx.doi.org/10.1080/02571862.2004.10635068

  • OldDutch

    Creosote is not completely harmless, however if the rrt are well weathered, what there is still to leach out of them is negligible. I very strongly doubt they are newly treated. If they are brand new ties remove them, otherwise don't worry about it.

  • digdirt2

    "It stands to reason, that if the creosote affects the soil biology, it would affect the nutritional density of the plants themselves. "

    And there is the flaw in the argument that has been repeatedly tested and repudiated. The maximum effect on any soil biology by any plant-based creosote toxicity remaining in the commonly used old RR ties consistently tests out as as little as 0.5" to a max of 6" max and that that range declines rapidly with exposure. 6" is the margin of spacing that is OMRI recommended when using them. Nor is there any scientific proof that the affected soil biology in any way affects the plants grown in it.

    This is an old issue, just like the claims made against pressure treated wood use, based on old practices that have long been discontinued and unsubstantiated claims of contamination. Keeping the argument alive and rehashing it over and over again only serves to confuse and create apprehension among new gardeners who chose to make their beds out of old RR ties. It is a personal choice. Don't use them if you don't wish to.


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