Re: [gardeners] Question about pressure treated wood

Harry Boswell (
Wed, 21 Feb 2001 18:46:38 -0600

I'll echo what George said - with one caveat.  I've made beds out of
CCA lumber for years, and have a couple now.  I don't *think* there's
a problem, although if I were growing carrots or another root crop,
I wouldn't plant within about 6" of the wood.

That being said - the place I work has a lab for testing air, soil, and
samples, and I think I'll see if they can test some of the soil from one of
old beds.  I'll try to remember to ask them tomorrow, and report back.

In the meantime - last year, I decided to do a test, using one bed of CCA
lumber, one of untreated lumber, and one of untreated-but-painted lumber.
So far, they're all holding up.


----- Original Message -----
From: "George Shirley" <>
To: <>
Sent: Wednesday, February 21, 2001 6:28 PM
Subject: Re: [gardeners] Question about pressure treated wood

> You will probably get 50 different answers to your question Jeannine. To
> 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
> soil. That being said it is also best that you not saw your treated wood
> 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 My raised beds were originally made with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
> 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.
> George
> 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
> >