Dead river birch
Hi my river birch started looking sick last year - the upper branches lost leaves, then started dying and dropping - covered with what appeared to be a black fungus or mold . I had a tree company trim the tops hoping to remove the ‘infected’ branches and give it a chance to recover but it now appears completely dead. Many of my neighbors also have river birches that are also now starting to look sick. Do you know what might be causing this - any treatments I can recommend to them? Can I plant another river birch in the yard or is this a disease that is affecting all river birch? The tree was 20 years old and had been very happy until last year.
We cannot say what killed your birch from the photo. Actually, once a plant is dead, it is usually impossible to say what killed it. If you can send us a closer view of your neighbor's trees, showing the parts currently infected (not already dead) our plant pathologist may be able to help. Try to attach several photos at closer and closer range.
River birches are not long-lived trees (like an oak.) These may be aging and getting more vulnerable to disease consequently.