Circular garden around a flag pole

I'm trying to design a perennial garden around a flag pole that is viewed from all sides.

The garden size is 20' diameter. The flag pole is in the center and is mounted into a 3' diameter concrete slab.
This garden is in zone 5 and gets sun most of the day.
It is located in front of the building.
There is a walkway leading to the building from a parking area which has perennials along both sides. Daylilies short,tall,early,late
roses, columbine, bearded iris, delphinium, sedum, peony,
asiatic lily,ligularia,yarrow)
The flagpole garden is about 30' away from the walkway.
Would you use same plants as the walkway or will it look like to much of the same?
How would you suggest to arrange the taller vs shorter vs early bloom vs late bloom plants?
Any advice would be greatly appreciated.

ANSWER

I think t would be nice if you used some of the plants already being used in the other area, but also added some new ones. This way, it will tie together but some other interest will be added.

I would go for plants that have a long period of bloom and look good for most of the season. Some additional plants you might consider are Nepeta 'Walkers Low', Sedum 'Autumn Joy', Salvia, and Thyme as a groundcover.

See Perennial Flowers

I would go for various seasons of bloom for interest. Place the taller perennials towards the center, medium sized ones in the middle, and lower ones along the outer perimeter. That being said, break it up here and there with some taller ones in all areas. Otherwise it will start to look too monotonous.

Also, try to change the textures of plants that are next to each other. Ornamental grasses, such as Fountain Grass provides a nice change and winter interest. 'Hamlen' is the grass I like to use as it gets taller (but not too tall) than some of the others. 'Moudry' is a nice grass too.

Nepeta 'Walkers Low' will bloom most of the season, on and off. It's drought tolerant too. Sedum 'Autumn Joy' blooms late summer/early fall. Thyme just looks good all the time (excuse the pun!) Good luck.