I have a river birch which is 13 years old and very large single tree and I'm concerned about the health of the tree. Subdivision is 16 years old, like all in the Aurora area the good soil was stripped away but the tree was planted in existing soil in large garden bed area about a 1/2" to 1" of new compose soil sits in the garden bed, been like this for 15 years when I built the house.
Each spring I have to watch for ants/aphids, which cause leaves to curls, turn white/black and drop so I use dish soap/water and spray the leaves and bait with ant poisen which helps that issue.
But now in the last 3 years I have noticed yellowing of the leaves in mid-spring to end of spring and beginning of summer. The portion of the tree facing east to south-east looks much better (greener, fuller) than the larger center portion of the tree that faces mostly to the west which doesn't seem to contain as many leaves and they are yellowish with sort of black spots on them. Also, just prior to spring bloom I noticed a lot of twigs/branches falling from tree during spring storms.
Concerned the tree is slowly dying and might lose it. Watching/looking for any sort of bore holes, don't see any but did notice wood peckers a few times pecking as something which concerns me, maybe they're trying to get to some sort of bore, or maybe just eating ants. Read that the yellowing leaves is sign of insufficient iron - so confusing - help.
