eventually the wood will rot and probably smell a bit and then yoiu will have aholo space...
so, why not start out with a concrete collumn instead of wood...i.e. replace the wood collumn with either concrete block or a cardbard tube from Home Depot (filling it with concrete) or something like that.
second, pushing the stones into concrete may not be the way a professional would describe the best technique (mortar is cement and sand, while concrete is cement sand and aggregate stone) but it might work as long as the stone adheres well. Spend some time at lloking closely at similare stone walls and columns to get a sense of how to do it. Then read about curing etc.
Then using stainless masons tabs or chicken wire screwed down etc. is indeed a good idea. Also using a masons glue (the kind you can find in your local hardwar store that is admixed to the mortar) is also helpful.
Asha

Thank you Asha:
The posts are holding up the porch roof... and I think concrete columns would be too much weight on the floor. It's really just a covered deck with a full roof. Do you have an opinion on cement backer board as a base to build off of? Would I have the same issue if I tiled the posts?

I'm just trying to hide those ugly plain posts.

Thanks also for clarifying the difference between mortar and concrete...

Thanks for your input!

if concret block is too heavy for the floor, then so it stone... tile is just as heavy per cu ft, but way less cu feet, usually... so tile on backer board works well...
still, you have to keep the wood post from rotting.
-A

You could try having the bottom half concrete covered with stone, and the top half wood.

-Audric