natural wooden fence post longevity

[Paul Wheaton]

I'm considering putting in some wood fence posts (I have lots of trees that need thinning and need some fence). I don't want to treat them (trying to be super organic), but I do want them to last a long time.

It seems that the primary problem with fence posts is that they rot at the soil line. The combination of moisture, soil microbes and air rot the post.

I've heard that cement is often not a good choice for a wood post because it holds moisture and, some say, makes the post rot even faster.

I keep thinking that there must be a simple way to do this .... The first thing that comes to mind is to somehow heep the water away from where the post contacts the soil. A teeny tiny metal roof seems crazy. Cement?

What if I put down a bunch of ag-lime? It seems that the alkaline around the post would be too high for nearly all of the microbials, while any runoff would be beneficial for my generally acidic soil.

Are these ideas too goofy? Anybody have other ideas?

[GeorgeK]

black locust is among the longest lived untreated fenceposts for ground contact. Concrete does help, provided the wood is completely protected from ground contact, and sloped such that water runs away and weeds are trimmed to keep air at the base of the posts

[SouthernThunder]

Soak em in crude oil. They'll last a long long time and it doesn't get any more organic than that.

[Meg Z]

I'd vote for the black locust, which you would want to take out anyway since it can be poisonous to livestock. Cedars are also slow to decay. You may be able to get some ideas on your indiginous species at your county extension office....or not, but it's worth a try.

Good Luck
Meg

[gobug]

You can use cement, but as mentioned above, be sure to encase the bottom completely and bring the cement above grade and slope it away from the post. I don't believe that cement is "organic", nor crude oil, so neither may meet your desires. You could mix boric acid with ethylene glycol and paint it on. It would soak into the log completely and preserve it. Once again, this may not measure up to your standards.

Another consideration would be to zig-zag your fence sections which would stabilize the fence geometrically.

[uncle Will in In.]

To bad you don't have some Osage Orange (hedge) to make posts out of. They last longer than the guys who dig the post holes.
You could use willow for posts. They will take root and grow. That way they never will rot. My brother used sassafrass for posts once. They grew. The old time farmers used white oak logs that they split and let dry for posts. They were pretty long lived. Abe Lincoln got his reputation for being a log splitter, and that was making fence posts.

[Cyngbaeld]

You can char the portion that goes in the ground. That will slow down decay considerably and is about as organic as you will get.

[bare]

Give it up Paul. You can tell all the advice is from elsewhere...Black Locust? Ossage Orange? (we do have a bit of that, but here, it's a shrub).

Just about anything we have growing around here that will last more than a few years without treatment, is Western Red Cedar, and the butt cuts from old growth Western Larch, split.

I've tried it all, over the years. Untreated larch and fir, home treated larch and fir, split cedar, round cedar, snow caps, and charing. The Cedar will last around ten years, the untreated larch and fir two or three.

Unless you really like building fence, I'd cut your wood up and sell it for firewood, take the money and buy treated round posts and T-posts, with railroad ties for corners and anchors.

If you are going to use cement, don't bury your posts in it, dig your hole, pour concrete in it and stick a metal saddle in the concrete. That way your wood is not in contact with the ground. Or you could do like I saw in Kansas and make forms and pour concrete posts.