Re: [gardeners] Question about pressure treated wood

George Shirley (
Wed, 21 Feb 2001 18:28:14 -0600

You will probably get 50 different answers to your question Jeannine. To the
best of my knowledge, and that's based on reading most of the literature on the
subject. The active ingredients in pressure treated wood do NOT leach into the
soil. That being said it is also best that you not saw your treated wood over
the soil but do it over plastic or cement where the sawdust can be swept up and
put in the trash. There is some schools of thought that the arsenic in the
preservative can leach out if the wood is turned into sawdust.

I see this same question asked on the web almost daily is the reason I said you
might get 50 different answers. My raised beds were originally made with
railroad ties. Railroad ties are preserved by pressure treating them with
creosote. After I replaced them (they were rotting badly) with cinder blocks I
took samples to a chemist of my acquaintance and asked him to test the soil for
foreign substances, in particular creosote. All tests came back negative,
including the samples taken from what would have been directly under the ties.
As they say everywhere on the net Your Mileage May Vary (YMMV).

If you are truly concerned you might try either cedar or cypress boards or
cinder blocks instead of the pressure treated wood. Hope this helps.


Jeannine Kantz wrote:
> I've been perusing several plans for building raised beds. One calls for
> CCA pressure treated wood. Is treated wood safe to use with plants that
> will be eaten? Does anything leach from the wood to the soil?
> Jeannine Kantz