Powdery Mildew?? on my Oaks

[CurSedVoyce]

Well, went out back today to swing my boy on his swing and check the garden. Low and behold, some oak coming out of a stump looked white and powdery on the leaves and they are curling. And a glance around the twelve acres, I found an Oak that is fully involved, looks white against all else. I have been researching and the best I can find is powdery mildew as far as symptoms and what I am seeing, just seems like the wrong time of year and such. We have been up in the humidity department but temps in the 90s. I will try and get some pics tomarrow.
Oak leaves white like covered with powder. New growth is budding out the stem past the damage. The leaves are curled and not healthy looking where powder is present and healthy on the new growth.
Tell me what ya'll think.
White oaks.... oops

[Paul B]

I see powdery mildew (http://www.agf.gov.bc.ca/ornamentals/publications/pesticide/disease/mildew.pdf) here on maples and such later in the summer, hot and dry or warm and damp weather seem to be favourable for it.

[CurSedVoyce]

The new growth coming out of the stump and past the powder seems fine. My Concern is the tree I see well involved. I don't see any new shoots coming out the tip of the branches like I do on the stump growth. I hope it survives ok. 18"dbh, twin trunk and about 45' high. Its a nice buffer between our two houses here at the seasonal creek. I would hate to lose it or see the creeping crud spread. As the trees lose thier leaves will this hinder it some or should I water down the oak?..

[TC3]

I'm not familiar with powdery mildew. It's a fungus, right ? I've never seen it on oaks.
I sometimes see what looks like powdery mildew when it is actually moldy aphid honeydew (excrement). Did you check for aphids ? I didn't think that oaks got 'em, but again I'm not familiar... Just saw 2 Pin Oaks last week with very heavy scale infestation, & I'd never seen that b'fore either.
Pics maybe ???

[treelooker]

very common on english oaks here. when it hits late in the season i usually don't worry about it. best of course to maximize light and air flow.

[Frans]

... best of course to maximize light and air flow.

I agree. Clean out the deadwood first, then if the canopy is totally thick, and it is dark in the canopy, a bit of thinning is good.

[CurSedVoyce]

Have plans on the dead wood and thinning, Bull pine right next to it too, So I may have to take it for more light, no biggie.
I'm not familiar with powdery mildew. It's a fungus, right ? I've never seen it on oaks.
"I sometimes see what looks like powdery mildew when it is actually moldy aphid honeydew (excrement). Did you check for aphids ? I didn't think that oaks got 'em, but again I'm not familiar... Just saw 2 Pin Oaks last week with very heavy scale infestation, & I'd never seen that b'fore either.
Pics maybe ???"

Yes I did check for aphids and mites, none apparent. As far as pics... wifey needs to hand over the camera, I will try and get some tomarrow. Better get some batteries too, I know her tooo well.. LOL
I really appreciate ya'lls input on this..