"Planting" is how it is referred to with peace poles.
Just dig a narrow hole with a posthole digger (shown below), set the peace pole in it, and then tamp the earth back in around it, perhaps with a 2-by-4. Stone poles need a hole 3 feet deep, others need less than 2 feet. There is no need to reach the frost line.
Using cement is unnecessary, but fine if the landscaping won't change in the next century or two.
Posthole diggers can be rented from tool rental companies for about five dollars per day or
purchased for under $25 at hardwares and at Amazon.com. Click the photo at left to see a video of one being used.
Below right is a hole typical for any stone or metal peace pole planting.
Alternative
Metal and resin also can be slid over stakes or posts.
For temporary stands, click here.

