River Birch Problem

[FrAnthony]

Hi,

I'm new to the site and I'm glad I found it.

I have a problem with a small grove of River Birch trees we planted three summers ago.

The first two summers they did fine but this year they developed a blackish fungus on them. It's killing the leaves and leaving the branches bare. It appears to start at the bottom of the tree and work it's way up. I've attached a photo. It is also all over the branches the branches too.

I would greatly appreciate any help with this problem.

Thanks

 

[Urban Forester]

Are their larger "overstory" trees above them? That appears to be sooty mold the excrement of soft shell scale insects. If it covers a large portion of the leaf it will inhibit photosynthesis causing the leaf to drop. If there are no trees above them, check the smaller twigs/branches for small "bumps" on the twigs. Google: Lecanium Scale to see what you MAY be up against. Aphids also release sooty mold, so check for small green or black insects on the leaves themselves.