Here is one of my birdbaths. Lg. pot with small tomato cage inside then stick a planter bottom in the top ring. There is room to plant under the bottom. This one which is on the left middle of the picture has Hens and Chicks planted in it.
Another one I used an old Water Bath Canner lid in it. It was in the shade so I use Impatiens planted in it.
I did get the idea from Birds and Blooms about 6 years ago.
The third one I planted with Moss Roses but the Deer used it for a Salad Bar!
They aren't fancy but they have worked very well for me. Plus they make a good Dog Waterer according to the dog.
Enjoyed looking at the pictures. Will have to go back and read later.