Just a follow up on the Echibeckia and the hardness. I'm in zone 7b and the plants didn't survive the winter even though we had a milder winter than usual. . Nursery where I bought mine is doing a bunch of backpedaling.
Oh well, just wanted to get the information out there. I'm sure if you are in zone 9 and higher these will be perennial for you. My feelings are not publishable, just wish the breeders would test plants before making claims and using the public as a testing field.