River Birch and Magnolia Trees

[danar]

My River birch was planted in the Fall , it is about 8-9 Ft, with multiple stems about and inch in diameter. It has begun to leaf out, and some of the leaves are distorted and walnut shaped. They have a gray powdery residue on the back, what is this and how do I treat it.
The other is a magnolia tree, about 25-ft, it looks like it is dying. From the top down it's drooping, the leaves are turning yellow, they have black spots on them, 3/4 of the tree is like this, the bottom 1/4 still looks green and the leaves are perky. What can be done? Thanks Dana

 

[Urban Forester]

Pictures would be a great help. There's multiple things that can cause your symptoms.

 

[treeseer]

Symptoms indicate root issues. Please post pics of the flare, where the stem flares out to form the primary roots.

 

[Urban Forester]

Pictures #1 and 2 seem to show the presence of erinose mites. I would need to see a much closer picture of the "white powdery" substance on the back side of the leaf to be sure. If this substance can be wiped off by your thumb it may be powdery mildew that is disrupting photosynthesis, if when you wipe, it feels granular, then odds are you just crushed a whole bunch of mites. Has this tree ever been treated w/insecticide? Mites on birch tend to appear when predators have been killed by spraying. The good news is that both these problems are not threshold issues. The tree (if otherwise healthy) will survive either, or both. The Magnolia is another issue, judging from its size I would guess its been there a while and not recently planted? The browing of the leaves could be stress related or a fungal pathogen. Is a close-up of one of the leaves w/spots possible? Has your area recieved alot of rain lately? Considering its Georgia, I would guess you've had high humidity, both these conditons could lead to infection by leaf spot fungi. This could also be a "first sign" of a root issue (google: girdling root) The "top to bottom" browning is consistent with that. A picture of the root flare would rule that out.