AusBonsai

pureheart wrote: ↑August 19th, 2020, 9:01 am Thanks I was wondering what where you using for the plant boxes! I'm just a noob in these things.... question the treated pine you used for the plant boxes isn't it going to harm the plant? aren't the chemicals leaking into the soil?

Some nasty chemicals are used to treat timber, but they're designed to not leach out of the wood into any surrounding soil, so chemicals affecting the plant shouldn't be an issue (from what I've read/understand).

I use old (untreated) pallets to make grow boxes - they won't last forever (maybe a few years if I'm lucky) but the price is right, so that's an option to consider if you're concerned about using treated wood.

Most manufacturers and garden sites say that using treated pine is safe and the chrome copper arsenic treatment used won't leach into the soil but in the late '90s it was found to have leached into ground water around the main wine growing regions of California and most wineries worldwide have since gone away from using treated pine for trellis posts and other things.

From my understanding it is safe(ish) to use CCA treated pine above ground, decking, outdoor buildings etc but becomes an issue when in permanent soil contact. I have hardwood planks 200x25mm for all my benches and apart from some slight warping they have been great