Beginner Gardening: Which flowers that are perennial that grows in 5 gallon pot, 0 by sunray2003

sunray2003 wrote:
I dont plan to move these pots so there will be sun outside most of the day outside.
Yes, they are standard 5 gallon nursery containers.
They are not wide containers and I think I would like to have 1 plant per pot.
I dont prefer anything hanging or a vine.
i think I would like something like Dahlia but last winter they did not survive. I did not protect Rose and Hibiscus either but they survived but the Dahlia completely went dead (atleast did not have any leaves and stems were all dry by the time winter ended)