"Theo Asir" writes:

So I went looking and this is apparently
not very well known but Downy Mildew apparently
causes these blotches on rose canes.
I couldn't even find a good picture but
try this one.

http://www.cruzio.com/~rbedard/devor...wnymildew.html

The last two photos of the leaves sure look familiar to me. I even brought a
couple inside so I could look at the leaf and photo at the same time. I think
you might have found the answer.
I've always used Dithane M-45 as one of my fungal sprays. All the articles I
found mentioned it was effective against DM. When I started using Banner Maxx,
I began using the Dithane less often. So that fits with my blaming Banner
Maxx.
It also mentions high humidity being a requirement, we certainly have plenty of
that here.
One of the non HT roses affected does get a lot of shade. The other non-HT,
Belinda's Dream is so very thick and full, even growing alone it can't possibly
get good air circulation.
I think I'll go back to using Dithane as my primary fungicide and see what
happens. Of course our temps stay in the upper 80's now so I should notice a
decrease anyway.
Maybe you're right again, Theo. Maybe...