its a deciduous tree ... i dont really care about leaves.. in what is now;. late fall ...

i would expect them to fall off.. after the insult of transplanting ...

also.. fall is big PM time ... so its not all that uncommon ... on a muoltitude of plants .... its just not a big deal ....

see link below for planting instructions ..

a pic might change my mind.. but i doubt it ....

ken

https://sites.google.com/site/tnarboretum/Home/planting-a-tree-or-shrub

This close to fall not much you can do. Once the leaves have dropped pick them up to limit out back for the up coming season. Powder mold does harm Dearing the growing season there is all kinds of sprays you can use even organic spray like dr. Bonner sal sud soap mixed with neem oil does a great job

Robert, I think of powdery mildew affecting the upper surface of foliage, not the underside. Can you remove an affected leaf and take a good picture or two?

I think that it IS important to know what it is now, as it might be something that could and should be tended to.

Powdery mildew starts on lower leaves/branches removing while still active can cause a out break. It's a mold moving it will release spores

Bulldog, the OP stated that there is a 'mold' on the underside of some leaves. My comment still stands....PM typically affects the upper surface of leaves, rather than the underside.

I'd very much like to see this 'mold', as should you, before suggesting a plan of action. Frankly, I'm suspicious that this is not PM but something else.

Yes to Rhizo and more generally, yes to identifying "pests and diseases", if actually present, before reaching for a control product. And yes too to the notion that by October, all manner of insect and fungi have had their way with leaves-temporary organs that the tree will reproduce next growing season-and that any control measures are quite likely to be unnecessary at this time. My gosh, if we were to panic about every landscape plant that has leaf blemishes in October.........we'd be a bunch of spraying nincompoops. Stuff is all beat up in the fall-this is normal! Please, let's not be applying pest control products outside of the growing season! To leaves that will soon be sloughed off by the plant! But do the work of identifying, so you know if there is any legitimate practice you should be undertaking, like raking up and composting all the leaves you can, that sort of thing.

Thanks for the comments everyone; I understand the leaves are about to fall I was just looking to identify it since its a new planting. I won't do anything until spring. Like I said before it is only on some of the leaves, and only on the underside.

Here's a picture:

Thanks for the information!

Powdery mildew. Pick up leaves when they fall..best treatment for the upcoming grow season..Dr. Bronner's sal sud soap and pure neem oil.

1 cup each to a gallon of water both produces are organic only harm you can do is treat the tree too much an it builds up a wax coat

Lots of work for "problem" which is nearly 100% cosmetic. Life is short....to each his own.

For the record, powdery mildews are favored by dry soil conditions, where plants are a little moisture-stressed, but at times during which there is significant atmospheric moisture, like all those foggy late-summer and fall nights and dew-filled mornings. But the pathogens responsible for this constellation of conditions we call powdery mildew do not require free water on the leaves to colonize them.