Permanent rent sign post

[Sam Leon]

I am trying to figure out a better way to avoid putting up a yard post every time a property is available for rent and remove it every time a vacancy is filled.

For single family homes, I think I will rig together a post where the mail box can be mounted on top of it, and I can simply add a hanging sign underneath when I have vacancy.

For multifamily the mail boxes are on the wall or doors, so I don't have anything in the yard that I can mount to.  

Plant a small tree out front that I can hang signs on?

Ideas?