prune now and that way the plants will have more energy in the spring

wrote:

I have two sets of flower-plants, one Hibiscus, the other Canna Lilly.

Both are supposed to be perennial.

They got pretty big this summer with nice flowers. I'd like to see
them come back next year same way.

Should I leave them be, should I prune them back, should I prune now
or in the Spring?

Thanks