As my spinach is growing away nicely in the poly tunnel with it's roots
touching the tannalised timber sides of the bed , it occured to me - is this
safe?

"Trevor" wrote in message
...
As my spinach is growing away nicely in the poly tunnel with it's roots
touching the tannalised timber sides of the bed , it occured to me - is
this safe?

Question is will the spinach lift the sides of the tunnel edging and escape
or will it just lie there dormant and surrender to the tough woodwork and
die?

"The Invalid" wrote in message
...
On Sun, 10 Sep 2006 21:01:46 +0100, "Trevor"
wrote:

As my spinach is growing away nicely in the poly tunnel with it's roots
touching the tannalised timber sides of the bed , it occured to me - is
this
safe?


I have a deep bed for some veg which uses Tannalised timber for the
sides with no problems

Any idea what chemicals they use in the process? I don't think they use
ARSENIC any more!

Trevor wrote:
"The Invalid" wrote in message
...
On Sun, 10 Sep 2006 21:01:46 +0100, "Trevor"
wrote:

As my spinach is growing away nicely in the poly tunnel with it's roots
touching the tannalised timber sides of the bed , it occured to me - is
this
safe?


I have a deep bed for some veg which uses Tannalised timber for the
sides with no problems

Any idea what chemicals they use in the process? I don't think they use
ARSENIC any more!

Unless I'm out of date, they still do. Tanalised timber is treated with
copper, chromium, and arsenic compounds. It's meant to be done in such
a way as to minimise leaching: it seems the main thing, assuming the
correct proprietary solution is used, is a long enough period of
drying, which fixes the compounds. One study, from New Zealand,
available on the Net reports some uptake of arsenic by spinach grown in
the kind of bed you describe, but according to that study it was below
the recommended level -- you can make up your own mind about that! I
don't think I'd be worried, but the paper's at:
http://72.14.221.104/search?q=cache:...&cd=8&ie=UTF-8
or:
http://tinyurl.com/hgka8

I think we've suggested before that, if one's worried, it would be a
good idea to line raised beds with plastic sheeting of some kind to
stop any soil contact with treated timber.

--
Mike.

Haven't got a clue but I haven't noticed any difference in the taste
and am still alive !

You probably wouldn't notice small amounts taste wise or health wise
immediately.
I think arsenic is one of those elements that builds up in your body over
time before its effects start to be noticeable - like lead, by which time it
is usually to late to undo the damage done. You may still live to be 100 but
it's the sort of thing that could knock off anything between a day or two
and a year or two, depending upon many factors. Of course larger doses are
fatal anyway.
--
David
.... Email address on website http://www.avisoft.co.uk
.... Blog at http://dlts-french-adventures.blogspot.com/

Bear in mind that moisture in the raised bed will travel outwards to
evaporate on the dryer side so it is very unlikely that anything in solution
would be taken up by plants in the bed. If there was the possibility of
dangerous chemicals being leached from such timber, I'm sure the EU would
have banned the use of it! If that timber is what is termed "gravel board"
for fencing, I've been using it for years and apart from growing another
head . . . . !!!!!

Geoff

They are sold as scaffolding board seconds. I have a mixture of tannalised
and non tanalised though no idea which is which.