TimR wrote:

I need to put up a fence for our puppy.

I plan on 4x4 PT posts, 4 feet above ground, 2 feet below.

I'm getting conflicting advice on concrete vs gravel vs just tamp the
dirt really tight. One expert even recommended concrete in buckets.
There seem to be several successful methods.

I want the posts to be removable eventually, for repair or moving the
fence area. So if concreted in, I'd want them to not be stuck to
it.

What do you think?

And yes, I know to call Miss Utility before digging.

Ditto on the pressure-treated posts someone else mentioned--toxicity issues.
It's also worth remembering dogs can dig pretty good, especially if they're
bored or frustrated. Don't sink the posts into the ground, use galvanized
steel brackets set in concrete (in buckets if you like); the posts nail or
screw into the brackets so you can remove or repair them later and are less
prone to rot. If need be you can later remove the posts and dig up the
concrete and the fence is gone. Also ditto on the shade, ample water etc.