Treated pine

[Tingalpa Permies]

We're planning a few new no-dig vegie patches for the back garden and were wondering what people's views were on treated pine as edging? We want to hear the good, bad and ugly. Thanks!

[thepoolroom]

The standard advice is to not grow food in beds lined with treated pine. The treatment is called CCA, which stands for copper, chrome, arsenic. Doesn't sound too good.

Does anyone know if the "Waxwood" treated pine is any better? It's a different process - I think they use heat and pressure to infuse some kind of wax into the timber, which protects it from moisture, rot and pests. I can't find much info on the net, and they seem to only sell from Albion Park Rail (near Wollongong).

[.Macca]

Much of the treated green tinged pine these days is ACQ (alkaline copper quarternary). This was recommended by the APVMA for 'sensitive' uses such as hand rails, playgounds etc. in 2006 and is much safer. We have used this for raised food garden beds.

.M

[Tingalpa Permies]

That's really interesting, thanks guys. We did get some treated pine last year and the seller said it was ok to use for vegie gardens, but you never know if they're just saying that to make a sale, or because they don't really know themselves. Now we know what we're looking for, I might ask if it's the ACQ stuff this time around, it sounds much safer!

[SueinWA]

Ask if the seller has any literature on the wood treament, then do your own research.

We have wood that is treated with the alkaline copper quarternary stuff here in the U.S., and here is the Material Safety Data Sheet (MSDS) for it: http://www.austinwholesaledecking.com/pine/msds.pdf

We also have some treated with what they call "Phospho-Ammonium-Boron Complex)" and you may, too. But it isn't rated for use on wood touching soil, as the borates tend to leach out, and that is the main ingredient that foils insect attack. Here is the MSDS for it: http://www.treatedwood.com/products/dblaze/msds.pdf

As far as I'm concerned, there are no really good, really safe wood preservatives that protect against UV, insects and mildew. If someone should come up with one, I think that person should be named Emperor of the Universe.

Sue

[nibs]

do you really need the treated pine?

i would suggest you use some old (recycled) pieces of hardwood, they should last a while and in my opinion look alot better.
or if you need a more permanent solution there is a lot of wasted bricks out there, you can just make a dry stone wall out of them.

i guess the point i am trying to make is that to takea piece of natural wood and treat it with preservative seems to me to be flying in the face of permaculture! what will the critters eat now? what happens to the wood after you remove it from your site, how does it decay? where does the wood come from? where do the preservatives come from? chances are that the answers are not pretty (at least as pretty as a neat trim garden bed) but they are questions we should be asking as responsible designers.

and if you plan on cutting the treated pine you will need to retreat the exposed ends with teh same preservative and to do that you actually have to hold a pesticide locence...

hope my opinion gave some food for thought.