Rust or mildew

McLean, VA(Zone 6b)

Has anyone experienced these on their coneflowers? I have several who's leaves are a very unattractive greyish/black, but they continue to flower, and it isn't spreading to the new leaves. I'm guessing it might be mildew.

Just wondering what type of treatment to use. I'll try to post a picture when I get home

McLean, VA(Zone 6b)

Finally, here are some pictures. I think that this is sunset. It is still producing nice flowers, but the leaves look bad.

Thumbnail by pennefeather
McLean, VA(Zone 6b)

And another shot

Thumbnail by pennefeather
McLean, VA(Zone 6b)

One last picture.

Thumbnail by pennefeather
Appleton, WI(Zone 5a)

I've seen that, in fact I've seen most of this on this link$department/deptdocs.nsf/all/agdex578/$file/630-2.pdf?OpenElement
always thought that was botrytis

McLean, VA(Zone 6b)

Al, thanks for the link. I don't think that this botrytis. From the discription that they have, the whole plant is infected and ends up dying within a relatively short period of time. My problem seems to be more localized, and presently is only affecting the leaves. Also, the leaves aren't falling off from my coneflowers. In botrytis, the infection goes up the leaves into the plant, and the whole thing collapses.

I am more inclined to think that this is due to mildew. I did see some powdery mildew on my magnus about a month ago. I sprayed that with an organic spray for mildew (I think may have been by Espoma), and it has cleared up completely. I probably should have sprayed this too as soon as I saw it, but I was hoping that it might clear up by itself. These two plants are several yards away from each other, so I don't think it spreaded from one to another.

Lakes of the Four Se, IN(Zone 5a)

Pennefeather, I vote for powdery mildew. My sunset plant kept getting this way until I finally moved it to a less crowded spot.

McLean, VA(Zone 6b)

Figaro, once I finally began using a spray for powdery mildew, they cleared up beautifully. I'm only sorry that I didn't do this right away.

I also had the same problem, but to a much less extent with the rest of my coneflowers. Once I begin to see that white coating in the future, I am going to attack them right away.

Orangeville, ON(Zone 5a)

what is the best spray for powdery mildew?

McLean, VA(Zone 6b)

I think the one that I preferred is Earthgrow (if that isn't the name, then it is pretty close; I finished the bottle, and haven't bought more yet). It was an organic spray, and didn't have the chemically smell that some of them have. I know that you can also mix milk and water, and that is supposed to be effective too, but I haven't tried that myself.

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