The top leaf is showing signs of serious chlorosis - lack of iron. This is often the result of high pH soils. Do you know what your soil pH is? The bottom leaf is showing evidence of maple gall mites. These are microscopic insects related to spiders that cause unusual bumps or growths, often brightly colored, on the leaves. The galls themselves are harmless and no treatment is required.

Don't know what the ph is but not sure what I could do about it anyways since the tree is ninety feet tall. Trunk is easy six feet diameter. Half the tree shows the chlorosis half not. This is the first time I've seen this in twenty years.

I'll give the iron supplement a try...although the I might go broke in the process!

Is the half that shows signs of chlorosis on one side completely?

If so, does this half of the tree sit near some concrete?

If yes, then I would pin the crime on the concrete. It is leaching lime or whatever it is that concrete leaches, and that is making that part of the soil alkaline and therefore the tree is unable to extract enough iron from the soil, as the higher pH has rendered it unavailable. Iron chelates is a great idea.

I live in northern Utah and had a Silver Maple that had the same problem. It eventually died and I found out that these trees do not do well in my area because our soil is too alkaline. I don't know why the nurseries around here even sell them because they all end up with iron chlorosis.

Where do you live? Is your soil acidic or alkaline? If it's alkaline you will be facing a never ending battle to keep the tree healthy.

This huge tree is at least fifty years old probably more like 75. Two years ago we found a huge carpenter ant nest that we removed. I know they don't hurt the tree but merely take advantage of the situation so I fear the old feller is heading toward that big mulch pile in the sky. I'll try the chelated iron treatment for a couple years and see what shakes. Thanks..