>I believe my zinnias may afflicted with powdery mildew. The flowers are
>fine, however the leaves look horrible. They have many white powdery spots
>and turn black/brown very quickly. I ended up ripping both my zinnia bushes
>out because they looked so sad after I picked the dead leaves off that I
>couldn't stand to look at them every day. Does this sound like powdery
>mildew? If so, are the seeds also affected? I have been saving the seeds
>from these plants, but if they are infected then I will throw them out. Any
>info you could give me would be greatly appreciated.
This will tend to happen to zinnias in the fall if a) they received
overhead water and b) they're in a spot that gets less than full sun. The
Sunset Western Garden
Book strongly recommends ground water only for zinnias.
I didn't quite get the drip system installed before my wife planted the
flowers this year (the main pipes and risers are in the ground). I am care-
ful to water on the ground only, but my wife is sometimes in a hurry and
will drench the plants with an overhead spray. The zinnias that are closer
to the trees, the ones that get more shade, are starting to get white spots
just like you have seen. The ones in full sun are O.K., but this may vary
depending on your local humidity and rain conditions. Western California
is still reliably dry.
Don't know about the seeds, but like you, I have noticed that the
flowers seem to be unaffected by the fungus.
Rainforest laid low.
"Wake up and smell the ozone,"
Says man with chainsaw. - John Ladasky