What constitutes safe? I doubt anything that can make wood very rot and bug resistant, is going to be completely safe.

I know they now market yellow wood down here in the states. Supposedly better than the old "green wood". I don't know how much better it really is.

Black Locust is a safe wood to use for posts, just keep in mind that it took 30 years or so to determine the CCA PT wood was not safe, and then another 10 years to get it banned.

or go with steel or plastic posts. I used old well drillers stringer pipe and chain link. Morning glories will cover a multitude of ugly fence sin ::smiles his jolly smile::

I've read that charring the underground part of the fencepost in a fire will keep it from rotting. Has anyone tried this? Seems organic enough, and worth a try, at the very least you know you aren't adding any more chemicals than you would have from a campfire.

Kyle

I heard that many years ago and tried it and found it is no more effective than just putting the post in the ground. Generally it is a waste of you time and energy.

I read about this glass-impregnated stuff a while back. I don't know anything about it, except that it's probably not very cheap.

Here is a link that might be useful: Timbersil

posts available are pressure treated with a chemical called ccq main component being copper.these posts are for ground contact.you can still get arsenic based posts but they are only sold for marine purposes.ask your lumber salesman what they sell.and only buy lumber from sustainable forests.to my knowledge ccq is not a harmful chemical.black locust,western cedar,and redwood are all organic options

In 2000, I built a greenhouse outside of Watertown, NY. We're pretty close to Canada. Being an organic grower, I used untreated lumber to build my Gable ends. I coated them with several coats of linseed oil, and so far, they're holding up. The posts extend 2' into the ground. Also, I used untreated cedar posts, again using the linseed oil, for the fence I built around my garden in the same year. All is well.

Almost all the western red cedar is from Canada from old growth forests. Almost all the redwood is CA second growth, but from depleted ecosystems and the rapid growth maens less rot-resistant oils in the lumber.

FSC lumber is the only eco-certified wood approved by Greenpeace, NRDC, WWF, FOE et al. The other certification is usually only industry approved. Reclaimed wood is best, but I think copper treated is fairly benign (unless of course it is cupric arsenide).

Concerning the black locust posts. I have locust trees on my property but don't know if they are honey locust, black locust, or other locust. How can you tell? Will any locust tree work? I have lots and would love to make use of them.

Go to your local office of the Purdue USDA Cooperative Extension Service and inquire of them how to determine what you have.

Here is a link that might be useful: Purdue CES

Untreated Osage Orange (Bodark) will outlast anything treated with cca or creosote. Oregon State University has a post farm where they planted a few of everything 70 years ago. I have just cut 400 posts and am drying them now.

Your decision, but read all the information available.

Here is a link that might be useful: Does Pressure-Treated Wood Belong in Your Garden?

Ditto on the Osage Orange Keith. Around here it is called Hedge and is highly valued for fence posts, very commonly used by ranchers putting up barbed wire fencing. I've seen posts having been in the ground in excess of 50 years that are still solid.

There may be another alternative, a show yesterday showed sodium silicate treated deck planking being used on a newly installed house deck. Apparently, the silicate (glass) gets infused into the wood sealing it up from moisture.

buffburd, charring does not hurt the garden.
But it only works on green wood,it heats the wood, pulling the slap out & harden(Heat treat) the green wood.Loin hunter have used this to harden their spearheads for hundreds of years.