Roses forum: Is this downy mildew?

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Name: Toni
Denver Metro (Zone 5a)
Whiskey Tango Foxtrot.
Charter ATP Member Irises Salvias Xeriscape Birds I was one of the first 300 contributors to the plant database!
Garden Ideas: Master Level Garden Procrastinator The WITWIT Badge Region: Colorado Enjoys or suffers cold winters Cat Lover
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Skiekitty
Aug 8, 2013 1:49 PM CST
It's been way more humid than normal for the past few weeks & I've noticed that some of my new roses I've planted this year are doing things like this:



Is this downy mildew? Treatment? I haven't seen it on my established roses, just "new" ones (ones I planted 2013).
Roses are one of my passions! Just opened, my Etsy shop (to fund my rose hobby)! http://www.etsy.com/shop/TweetsnTreats
Name: Porkpal
Richmond, TX
Charter ATP Member I was one of the first 300 contributors to the plant database! Keeper of Poultry Farmer Roses Raises cows
Garden Ideas: Level 2 Celebrating Gardening: 2015 Plant Identifier
porkpal
Aug 8, 2013 2:05 PM CST
I don't know - too hot here to be a problem. I didn't think it was a summer affliction...
Porkpal
Name: Toni
Denver Metro (Zone 5a)
Whiskey Tango Foxtrot.
Charter ATP Member Irises Salvias Xeriscape Birds I was one of the first 300 contributors to the plant database!
Garden Ideas: Master Level Garden Procrastinator The WITWIT Badge Region: Colorado Enjoys or suffers cold winters Cat Lover
Image
Skiekitty
Aug 8, 2013 2:10 PM CST
porkpal said:I don't know - too hot here to be a problem. I didn't think it was a summer affliction...


HAHAHAH!!

sorry, don't mean to laugh, but I only have 2 forms of weather here.. Winter & FH! Summer. And I don't think I'd have that kind of problem in the winter.. mainly 'cuz don't have leaves or they're dried up from the cold.
Roses are one of my passions! Just opened, my Etsy shop (to fund my rose hobby)! http://www.etsy.com/shop/TweetsnTreats
Name: Porkpal
Richmond, TX
Charter ATP Member I was one of the first 300 contributors to the plant database! Keeper of Poultry Farmer Roses Raises cows
Garden Ideas: Level 2 Celebrating Gardening: 2015 Plant Identifier
porkpal
Aug 8, 2013 2:15 PM CST
Well, since it's not winter there, it must be too hot for the powdery mildew... right?
Porkpal
Name: Toni
Denver Metro (Zone 5a)
Whiskey Tango Foxtrot.
Charter ATP Member Irises Salvias Xeriscape Birds I was one of the first 300 contributors to the plant database!
Garden Ideas: Master Level Garden Procrastinator The WITWIT Badge Region: Colorado Enjoys or suffers cold winters Cat Lover
Image
Skiekitty
Aug 8, 2013 2:25 PM CST
PPal - No idea!! I don't think it's powdery mildew.. that's white & this is definitely black. I *do* know that summer's on it's last legs, though. The geese have been flying south now for about 2 weeks. This has to have been one of the shortest growing seasons I've ever seen in my life. Barely over 3 months. Bleh.
Roses are one of my passions! Just opened, my Etsy shop (to fund my rose hobby)! http://www.etsy.com/shop/TweetsnTreats
Name: Porkpal
Richmond, TX
Charter ATP Member I was one of the first 300 contributors to the plant database! Keeper of Poultry Farmer Roses Raises cows
Garden Ideas: Level 2 Celebrating Gardening: 2015 Plant Identifier
porkpal
Aug 8, 2013 2:48 PM CST
I think powdery mildew can involve black patches as well as white fuzz, however I've never actually seen it. Summer here is still in full force: 103 again today.
Porkpal
Name: Toni
Denver Metro (Zone 5a)
Whiskey Tango Foxtrot.
Charter ATP Member Irises Salvias Xeriscape Birds I was one of the first 300 contributors to the plant database!
Garden Ideas: Master Level Garden Procrastinator The WITWIT Badge Region: Colorado Enjoys or suffers cold winters Cat Lover
Image
Skiekitty
Aug 8, 2013 3:14 PM CST
yuck. Yesterday I think it got up to 68degs. Right now, it's 72degs. RealFeel is 77. I'm loving this kinda weather. And so aren't the weeds in my yard.

Roses are one of my passions! Just opened, my Etsy shop (to fund my rose hobby)! http://www.etsy.com/shop/TweetsnTreats
Name: Porkpal
Richmond, TX
Charter ATP Member I was one of the first 300 contributors to the plant database! Keeper of Poultry Farmer Roses Raises cows
Garden Ideas: Level 2 Celebrating Gardening: 2015 Plant Identifier
porkpal
Aug 8, 2013 4:12 PM CST
106 now.
Porkpal
Name: Shrey Patel
West Chester
Fan of Flowers
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shrey
Aug 14, 2013 3:41 AM CST
Hi Skiekitty,

Downy Mildew is a very common disease of Roses which occurs under "Moist Cloudy Conditions". The disease is found throughout the United States, Europe and South America. All species of cultivated and wild rose seem to be susceptible.

SYMPTOMS:-
Under cool and moist spring conditions, young leaves stems and flowers may manifest purple to red or brown irregular spots. As the disease advances, lesions on leaves become angular and black with the possible appearance of white mycelium on the underside of the leaf. Advanced infections will have yellowing of leaves with brown necrotic areas and noticeable leaf abscission. As the scientific name indicates, the production of spores is sparse and therefore this disease is difficult to diagnose. Along the coast of California where moist cloudy conditions persist through summer, the disease is severe and can occur on large canes as purple irregular blotches

-Downy mildew appears on our garden roses only when these ideal, or at least very favorable, conditions are present.

They are:
Humidity over 85%
Temperatures under 80°

Downy Mildew Color-Black, Purple, Dark Red(leaf)

Powdery Mildew Color-White(Young Leaf)
[Last edited by shrey - Oct 28, 2013 11:48 PM (+)]
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