[davidg]

Every once in awhile, I see a condition in Goldsturm Rudbeckia: The whole plant turns black, then brown -- almost as if it dried out. But, it doesn't seem to be caused by drought. Seems like it's a disease or a pest.

Anyone else seen this?

[stoneridge]

I found this a while back:

"There are a few diseases that affect Rudbeckia. Septoria (a fungus) is one of them, and the most common of them all. There is also a bacterial blight. Both look very similar as the diseases progress. The best method for proper ID would be to take some samples to your local extension office to have sent to the university plant pathology lab for culture.
If it's Septoria, santitation practices done now can help for next year, as well as applications of the appropriate fungicide."

[Greensmith]

I have seen this also, a neighbor of mine lost a beautiful stand in a matter of weeks. The grove had to be a good 8' deep and 15 wide.

It looked like it was drowning and then suddenly the whole thing was black in days.