I have a lot of them - in various locations around my house. Variety of
sun/shade conditions. Mostly sun with a bit of shade. None of them have
bloomed this year or last year. Other flowers close to them bloom and do
well...

They are thick and bushy. Get the same water and food that their close
neighbors get. They did bloom year before last and were just beautiful.
I have a bunch of Husker's Red Penstemon that have done wonderfully.

What gives? Any requirements I don't know about? I am in Atlanta and it
does get pretty cold here. Down to 10 or 12 degrees F some winters. A
lot of the low twenties. I add this because a lot of people seem to
think we are very close to Miami...

I've done my net research and now it's time to ask the real people.

TIA