I've never done it...always mixed with water. Has anybody had good luck just dumping the dry mix in the hole around the post?

Placing concrete around a wooden post causes it to rot.

I have "dry bagged" deck posts many times. As far as I can tell, it works fine. I'm interested what others say.......

......but I always had a good bit of gravel on the bottom of the hole.

Same as above and never had a problem.

We always dump little water in hole first, couple gallons, dump dry concrete in then gallon or 2 on top. Big pours we get concrete truck. But probably several hundred with dry bags. As stated I won't do it with wood post, pipe only. Wood rots inside concrete and leaves a gap fir moisture and that speeds up the rotting process. Good hedge post lasts longer with no cement.

I know pole barn builders that tamp dry mix around the poles they put in the ground. I have never seen or heard of issues doing that.

What Yes Sir said

I would mix it first. That way you know it was mixed completely threw! No dry spots!

Rot with treated 4x4???

I saw a pill box on Adak made out of bags of cement stacked There was a I beam down the center and bags on top. The shooting ports were from ground level up about 4-6 inches. You went down steps and around a corner to get in. It would have been made in the 1940's and was still there.

I don't know what your building but when we build fence we want it to last at least 2 or 3 generations. If a good hedge post will rot in concrete I promise a treated 4×4 doesn't stand a chance.

If you’re going to use concrete, it goes in the bottom of the hole well below the frost line. It acts like a pad and the post sits on top. Wrap the post loosely with tar paper so frost doesn’t grab it.

Hmmm. It's a landing/small deck out a door.

After I retired from grazing cattle, I removed all my high tensile wire, steel T posts and pressure treated wood fence posts. Regarding rot to posts, 90% of the rot occurs in the top 8 - 10" of soil.
About halfway through building my fences, I began backfilling and packing the posts with limestone gravel. Years later many of them hardly showed any sign of being in the ground at all.
If nothing else, pre-treat the post with a decent oil based stain, just the 12" that will be from the soil surface and down.

I understand. When I read post, fence post is my first line of thinking

I own a pole building company and have seen it done many different ways. I pretty much agree with what the others said. We mix with water in an electric concrete mixer and pour it in the hole. It won’t pass inspection otherwise. Never concrete around the post.

Phil Brown knows concrete. Phil, what say you?

A couple concrete guys always said to mix properly before dumping in holes. Some farmers I know use dry bagged right down the hole.

https://www.quikrete.com/athome/settingposts.asp

The manufacturer of the concrete says that's the way to do it.

I would tar the post up to the expected dirt level. An a wrap of plastic wouldn’t hurt after you tar it. But yes concrete will eat up a wood post treated or not. Also have noticed a difference in a post that just had the bag dumped around it vs one that had mixed cement around it. Seemed like the dumped bag never cured. But the mixed bags did. Kinda like the cement on the outside absorbed the moister an hardened a the inside wasn’t able to get enough moisture to set up a cure. Just the two cents from this concrete guy

Don't know if it is right or wrong but we have done a lot of pipe posts that way and they are still like we put them

I have a 6" 3/8" wall gate post that has 12 or so 80# bags of dry sackrete around it. I am confident that it will never lean or be pulled up with anything short of a D9