Help, what is wrong?? All my rudbeckia are dying. This includes newly planted ones as well as the ones that are one and two years old. The leaves start turning gray/brown and then the blooms dry. Since this has started I have watered alot, then watered every few days, I even mulched some to see if that would help. Nothing I do seems to work. Any ideas??

Here is a link that might be useful: Dying flower pictures