Have you tried growing any Dahlias? They grow rapidly in warm weather. They are usually started from tubers, which may be hard to find at this time of year, or cuttings rather than seed. You could buy some potted Dahlias and plant those and also at the same time take cuttings from the mature plants in order to make more plants. If you're buying potted Dahlias make sure you don't get dwarf bedding varieties.

Steve:
Yes, I do have tubers planted and the plants are doing well. First time that I am trying them but I was blown away by how long a season they had in a friend's garden last year!
Nancy