Texas Gardening: What's up with My Butterfly Bush?, 1 by bariolio

bariolio wrote:
I have 2 Black Knight BBs and they are doing very well this year with butterflies on them and lots of blooms. BUT they have a disease of some kind, which they had last year. 2 out of 3 died, I replaced one and these 2 have done better but the same thing is happening. The leaves start getting yellow and have brown crispy spots and eventually die. The stems also have some black on them. Anyone know what this could be? Here are some pics from last year. janet