[Arid_gardener] Powdery Mildew on Roses

[Olin Miller]

According to http://cals.arizona.edu/pubs/crops/az1033.pdf

"Disease is favored by moderate or high humidity and low light
intensity, conditions which are often prevalent on lower plant parts or
in thick foliage. Powdery mildew is found throughout the low desert
areas most of the year. At higher elevations, disease appears as host
plants begin to grow or develop new foliage. It is favored by warm
temperatures and is one of the few foliar diseases that is prevalent in
the desert areas."

According to http://cals.arizona.edu/pubs/garden/az1306.pdf

"It is a seasonal problem that thrives with cool, damp nights, warm
daytime temperatures in the 70s or above, moderate to high humidity, and
poor air circulation.

Olin Miller
Master Gardener Volunteer, Maricopa County AZ
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----- Original Message ----- From: <KLH718 at aol.com>
Sent: Thursday, May 11, 2006 6:21 AM
> What is Powdery Mildew indicative of?  Watering schedule off?  Soil
> composition off?  Sunlight access off?  Disease?  All of the above?
> I know I can spray my roses with chemicals - tried that (it works!) -
> but
> hate chemicals.