with Jennifer. Do not buy the fancy ones in bloom in the fall. I don't grow them here in Florida, but I have planted several in my daughter's garden in Salt Lake City in recent years and for sure, the ones we planted in bloom in the fall never made it to springtime.
Buy good hardy varieties from a reputable nursery in the spring, and they will be truly perennial, bloom like crazy and last for many years. You can also divide the plants in the spring to spread around the ones you like best. Maybe ask your neighbors for a division of the nice ones they have? Again, divide in spring when the new growth is less than a few inches tall.
I also think they survive better if not cleaned up until spring. The dead stems help to mulch the plant, maybe?