Sounds like a great idea. Sort of like mixing plants in a perenial garden so something is always in bloom.

Canna are so hardy and spread so quickly, that I have a hard time imagining something that you could plant there that would work as a winter season mirror. In the Summer the winter bloomer would be completely overrun.

I'm thinking something hardy like Trailing Lantana, but this will brown with a good frost and is not a good winter choice. You might consider that shorter thin leafed species of Streletzia. Bird of Paradise bloom late in the year and continue to have flowers well into January. But they would overtake the Canna and would be year round.

I would look for some sort of bulb or tuber plant and experiment to see if they could co-exist and compete.

One possible that comes to mind that blooms late in the season is cyclamen. These however do better in part shade I think, but might be a good experiment.

Dear Bearstate:
Thanks for your ideas. I was thinking watsonias, since they
are domrmant in the spring and summer, and come out late fall, when my cannas wane. Other plants you suggested, like
lantana and streletsia, are green and blooming perinials that never go dormant(unless there is a freeze, in which case, the lantanas recover in a few weeks, the streletzia has never been damaged by freeze) I am going to reduce the amount of cannas...just can't give that much of my garden to something that is ugly for a good four months of the year.

Thanks for your ideas.