Oh, I'd have to scroll back to look, but I don't think It was me who wondered about the temperature. I've grown them for many years... I've had other problems... Gophers mainly, but the lowest we've gotten here is probably the low 20's, with high 20's being typical most years. I have some that are wimpier growers than others, and I will admit to killing some in containers, but that was most likely forgetfulness with watering.
I'm hoping to add some more this year....just as soon as I get those tall beardeds planted.....