Hi all,
I want to build several raised beds for a vegetable garden. I may have the opportunity to get some old (20 yrs) telephone poles to use. I've read conflicting information on the internet regarding if these would be safe to use. Some sites say don't use them at all, and some say if they are that old, the toxins would have leached out by now. Does anyone know if that's true?

Better safe that sorry. Old poles are soaked to the bone in creosote. Thats why their that horrible brown color. And while some of the surface toxins might have leeched out by now, there is still a great deal on the inside. I wouldn't use them.

My understanding of the EPA position on creosote is that there are no registered uses of creosote for residential use, so there is no data concerning its safety for that use. That is, businesses cannot buy creosote for the intended purpose of treating wood and selling it to you for use in your garden. It can only use it for its registered use, such as treating utility poles and railroad ties.

http://www.beyondpesticides.org/news/daily_news_archive/2003/12_22_03.htm

So the data is not there as far as I can see. People may sell used ties and used poles and tell you it's safe, but it is likely that they have no data to back up the claims. Those who claim it's safe because they've used them for years with no problems are not worthy of consideration. (The same claim is made by some ancient smokers.)

At least that's how I approach the issue. The abandoned garden I took over last year had been ringed with rotting ties for a couple of years. I've been removing them all and carting away the surrounding soil within a foot or so of the wood.

Used ties and poles are cheap. Life isn't.

Wayne

Numerous studies have been done that show that the creosote will flow down into the soil not more than 6 inches from the pole although it can go several more inches deep. If you do make beds from these keep your plants so the roots will not invade that space 6 inches from the pole edge you should be alright. However, a good organic gardener would not use them.

Would it make sense to line the inside of the bed with thick plastic or vinyl sheets?

Why would you want to put plastic in your soil?

To prevent the creosote or other chemicals from leaching into the soil from the poles.

Tell you what, it would be a better idea to watch out for people clearing a stand of evergreens. They can be used, naturally rot-resitant, and no harmful chemicals to leech into the soil. Forget the telephone poles.

That will not prevent the harmful products from leaching into your soil. Maybe a liner of that sort would keep the harmful products from your plants but plastic contributes harmful by products to the soil itself.
There is no good reason to ever use plastic sheeting in the garden.

http://extension.missouri.edu/explore/agguides/hort/g06985.htm

Creosote, which is used to treat railroad ties, may cause injury or death to plants that come into direct contact with it. After a few years the effect diminishes. Old, discarded ties do not injure plants (Figure 3). However, injury may occur if ties are still oozing black, sticky creosote or smell intensely. If you are uncertain about the safety of treated lumber, place a heavy plastic liner between the treated lumber and soil used for growing plants to prevent direct contact of plant roots with the treated lumber. Be careful not to tear the plastic when tilling the bed.


I don't have raised beds, myself. I don't really need them. I'm just trying to help sonja_p find a way to use her poles.