For square foot gardening, I was thinking it might be cheaper to use
landscaping timbers that have two flat sides, drill holes near the
ends with two of them stacked, and then drive 1 in. EMT conduit into
the holes to fix them into position---- like I have seen done with
raised flowerbeds. Untreated wood would probably rot in a short time.
But what about growing veggies? What are the chances that toxins could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into the
plants?

"geronimo" wrote in message
...


For square foot gardening, I was thinking it might be cheaper to use
landscaping timbers that have two flat sides, drill holes near the
ends with two of them stacked, and then drive 1 in. EMT conduit
into
the holes to fix them into position---- like I have seen done with
raised flowerbeds. Untreated wood would probably rot in a short
time.
But what about growing veggies? What are the chances that toxins
could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into
the
plants?

I did square foot gardening for several years but at my age the
weeding and work just got to be a bit much. So, I switched to Earthbox
http://www.green-trust.org/freebooks/Earthbox.pdf

I'm in south Texas and the heat is extrordinary this year. As a
result, when I went to put in the fall plants, the Walmart storage
bins I use just crumbled. I went to Tractor Supply Company and bought
6 40 gallon rubber tubs (used to water livestock) and am going to make
earthboxes out of them. I'm tellin ya, once you get them built
gardening is an absolute joy. It's the ticket for lazy folks like me.
All you do is water and replant for the seasons.

But what about growing veggies? What are the chances that toxins could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into the
plants?


My ten-year-old raised beds are constructed of approximataely
twenty-year-old CCA-treated "landscaping" timbers of the type you
describe and my dain bramage is hardly noticeable! Typically, such
timbers are dipped but not pressure treated; treated timbers will bear a
tag indicating depth of penetraton. Of course, some portion of the
arsenic leaches into the soil and _may_ (under specific circumstances)
be taken up by vegetables -- root vegetables and potatoes, in
particular. Arsenic also occurs naturally in soil and is taken up by
veggies. Outside of an agenda-driven popular press, I have not seen a
single study definitively establishing a link to human health at the
concentrations commonly found. Moderatly-priced soil testing kits exist
for the consumer market. The issue of arsenic in garden vegetables is
not at all related to that of transference of arsenic from new,
unweathered CCA-pressure-treated wood onto the hands and into the mouths
of children from treated wood playground equipment.
Bear in mind that neither reason nor empericism has a place among
the agenda of the world-changers who depend on strident and persistent
FUD to spread their views and to bludgeon society at large into
acquiescing. While they may be useful for studying gardening techniques,
skills and old-timey lore, I suggest that you view with skepticism
"studies" cited in popular publications with "Organic", "Green" or
"Mother" in their names: Their POV is implicit and any "conclusions" not
to be trusted. You may find this document from the Penn State College of
Agricultural Sciences of some help in making your decision:

http://pubs.cas.psu.edu/freepubs/pdfs/uc173.pdf

I direct your attention to the beneficent effects of high levels of
organic matter/compost in garden soil and of simply peeling root crops.


All that said - and thank you for saying it.
I used cedar for my food-raised beds.
and for the touchy-parts of the kids play centre.
Green-Treated wood for the rest.
Calculate the cost difference - in my case - not much.
Peace-Of-Mind ... priceless.
John T.

They use copper napthenate to treat the lumber now, not the copper
arsenate they used until about 5 years ago. Copper arsenate was made with -
you guessed it - arsenic. Toxicology reports would suggest that the old
style was about 12 times as likely to cause problems as the newer ones.

That said, you can always line the wood with something, like plastic, or
even sheet metal.

In my case, I simply built my raised bed using concrete blocks, done two
blocks high. I lined it with very thick poly film. In retrospect, I think
if I had it to do over again, I would probably just buy a bunch of ge
silicone II, and apply it with a paintbrush to the inside of the blocks.
The blocks are working out pretty well, though.

On Aug 27, 12:40*pm, geronimo wrote:
For square foot gardening, I was thinking it might be cheaper to use
landscaping timbers that have two flat sides, drill holes near the
ends with two of them stacked, and then drive 1 in. *EMT conduit into
the holes to fix them into position---- like I have seen done with
raised flowerbeds. Untreated wood would probably rot in a short time.
But what about growing veggies? What are the chances that toxins could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into the
plants?

I had 2x8" raised beds which I ended up removing & just leaving the
bed sort of humped up a little, Thus it was much easier to hoe between
the short rows with a narrow weeder. Also if you ever want to use a
tiller again, no borders welcome. I turn over my beds at the end of
the year or in spring with a spade & it was harder with the frame in
place. And there not natural.
Dav
Dav

I am inth eprocess of building some raised beds for next year. I will
be using the plastic lumber or Trex, whichever is cheaper. I used
Trex whenever it first came out years ago to use as a border instead
of that cheap plastic stuff that comes in a roll. It is still as
perfect today as it was all those years ago, albeit a little washed
out looking since it has been sitting in the sun for years.

This stuff is made from recycled milk jogs and sawdust. You just need
to use a few more posts as this stuff bends quite a bit. Once in
place, it needs stiffened. On the plus side, you can use it to make
all sorts of shapes and such in the garden.





On Aug 27, 12:40*pm, geronimo wrote:
For square foot gardening, I was thinking it might be cheaper to use
landscaping timbers that have two flat sides, drill holes near the
ends with two of them stacked, and then drive 1 in. *EMT conduit into
the holes to fix them into position---- like I have seen done with
raised flowerbeds. Untreated wood would probably rot in a short time.
But what about growing veggies? What are the chances that toxins could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into the
plants?

"Dav" wrote in message
...
On Aug 27, 12:40 pm, geronimo wrote:
For square foot gardening, I was thinking it might be cheaper to use
landscaping timbers that have two flat sides, drill holes near the
ends with two of them stacked, and then drive 1 in. EMT conduit into
the holes to fix them into position---- like I have seen done with
raised flowerbeds. Untreated wood would probably rot in a short time.
But what about growing veggies? What are the chances that toxins could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into the
plants?

I had 2x8" raised beds which I ended up removing & just leaving the
bed sort of humped up a little, Thus it was much easier to hoe between
the short rows with a narrow weeder. Also if you ever want to use a
tiller again, no borders welcome. I turn over my beds at the end of
the year or in spring with a spade & it was harder with the frame in
place. And there not natural.
Dav
Dav

==================

Why do you turn your beds over, and how deep?

geronimo wrote:
For square foot gardening, I was thinking it might be cheaper to use
landscaping timbers that have two flat sides, drill holes near the
ends with two of them stacked, and then drive 1 in. EMT conduit into
the holes to fix them into position---- like I have seen done with
raised flowerbeds. Untreated wood would probably rot in a short time.

It depends on the timber. You can get untreated timber that will last 40
years or more in contact with the soil. Talk to you local timber merchant
to what is available in your area and the price. OTOH you can use concrete
blocks and other building materials that will last in contact with the soil.


But what about growing veggies? What are the chances that toxins could
get into the vegetables from the lumber if it's treated? Has someone
actually tested to see if arsenic leaches out and gets taken into the
plants?

I believe such tests have been done but I don't have a link. This is a
hot-button issue and all I can say is you should do your own research and be
comfortable with the risks you take (or don't take) based on solid
information and expert opinion. Such information and opinion may or may not
be available here.

David

OhioGuy wrote:
They use copper napthenate to treat the lumber now, not the copper
arsenate they used until about 5 years ago. Copper arsenate was made
with - you guessed it - arsenic. Toxicology reports would suggest
that the old style was about 12 times as likely to cause problems as
the newer ones.
That said, you can always line the wood with something, like
plastic, or even sheet metal.

Upon inspection, the first bed I built with the old treated wood and lined with
rubber floor mat material is rotting where the rubber is pressed against the
wood by the soil. Pull the rubber back, and there a gaping holes visable in the
wood. The outside of the wood shows little damage. I am not sure whether wood
exposed directly to the soil would have rotted as much.

On Mon, 28 Sep 2009 15:01:41 -0700, "Bob F"
wrote:

OhioGuy wrote:
They use copper napthenate to treat the lumber now, not the copper
arsenate they used until about 5 years ago. Copper arsenate was made
with - you guessed it - arsenic. Toxicology reports would suggest
that the old style was about 12 times as likely to cause problems as
the newer ones.
That said, you can always line the wood with something, like
plastic, or even sheet metal.

Upon inspection, the first bed I built with the old treated wood and lined with
rubber floor mat material is rotting where the rubber is pressed against the
wood by the soil. Pull the rubber back, and there a gaping holes visable in the
wood. The outside of the wood shows little damage. I am not sure whether wood
exposed directly to the soil would have rotted as much.

My understanding is the treating chemicals prevent insect damage but
do little if anything to prevent dry rot from constant exposure to
moisture.