Take a look at Miscanthus sacchariflorus if you want a hardy and very tall, spectacular grass specimen. Clumping bamboo such as Fargesia murellei, and hardy Hibiscus moscheutos all come to mind as well. A nice groundcover of hardy Baltic ivy along the pathway...which will soften the rigid lines of the concrete.....and maybe some "scotch moss" which is a bright geen moss-like ground cover would be a nice contrast to darker green foliages. Jazz it up with some pots of bright annuals such as nasturtiums.....which can be shifted around as needs and whims dictate, and you should have a lovely sanctuary!

Some hardy big-leaved trees in the background of the gazebo would give nice structure for your garden. Or any hardy but tropical looking plants for that matter. Getting the bananas, cannas, palms, etc., in for the summer and stored for the winter is lots of work so anything that can be left year in and out is gonna be a big labor saver. I am not familiar with what is and isn't hardy in your zone, but I am thinking about things like catalpa tree, Paulwonia tree, rice paper plant, maybe gunnera. Good luck! It looks like it is going to be a great addition to your garden.

Thanks Don and Eken... I appreciate your advice.

The concrete is all cured and I've set up the
fountain in the circle, so things are moving along!

Thanks again!
Tom