Will treated timber kill my native trees?

[fyzygy]

The past year or so I scavenged a couple of timber sleepers for gardening -- obviously some kind of treated pine slabs, square-cut, commonly seen in retaining walls etc. One I had resting up against (making contact with) the trunk of a native tree (some kind of eucalyptus I think). A few months later, that tree appears to be quite dead. Maybe the tree died for some other reason, not that I can readily think of one. If my suspicions are correct and the treated timber is actually toxic, why the fuck would anybody put it anywhere near their homes and gardens? 

 

[Halcyon Daze]

Not toxic to plants from what I know, but I don't like the 'sound' of any kind of wood up against a eucalyptus. They can be sensitive to fungal pathogens in the lower trunk/roots which may have been involved. 

 

I've used hundreds of treated sleepers over the years and haven't had any problems from them. Can't say they were ever touching a trunk though, so I don't really know for sure.

[saguaro]

is it green? Sounds like it's treated with chromated copper arsenate (CCA).

 

generally considered safe in contact with soil, pollutants more mobile in acidic soil. High risk of cancers and pollution with burning. CCA ash even cause localised skin cancers. I wouldn't be making a raised veggie bed out of it personally, but I doubt it is responsible for killing your eucy. Still, as Halcyon mentioned, it's a good idea to keep organic matter off the trunk of a tree

 

On 20/12/2021 at 9:35 AM, fyzygy said:

If my suspicions are correct and the treated timber is actually toxic, why the fuck would anybody put it anywhere near their homes and gardens? 

Lasts much longer.

 

Brings back memories of a certain 'eco' backpacker I stayed at where they burned treated pine in an open fireplace out the back