Florida has a number of Phlox species, almost all found in forested settings. The common roadside species (Phlox drummondii) is not a Florida native (Texas) -- it is a North American native and not believed to be harmful to the ecology of Florida as it spreads almost exclusively in disturbed, sunny areas (old fields, roadsides). Phlox can be either annual or perennial depending on species. Most grow as annuals. We encourage you to use species found naturally in your area.  Some phlox are annuals; some are perennial. Wildflower garden, typically q shade garden.