Please help identify a "persistant" leaf problem (mineral, roots, fungus)?

Would someone help me identify some problems on some new growth and old growth? the problem is mostly my maples, but I seem to have it on a cherry and a pear, and a fringe tree, too. Not all of my maples have "it". My soil mix is approx 80% sifted turface, 10% turkey grit, and 10% sifted pine bark fines. I defoliated a Trident forest and approx 5% of the new leaves have dark brown drying blotches and some of the leaves are curling. I water at least once per day, in the morning; and at dusk when I get home from work if they look dry. I wonder if I am watering too much. My soil mix is very free-draining. I have sprayed neem oil three times (approx two weeks apart) during the past 2 months. Here are the pics:

First is Acer rubrum (Red Maple, first year's leaves)


Trident Maple, new growth


Acer ginnala (Amur Maple)


Prunus (weeping cherry)


Sweetgum (Liquidamber)


Pyrus (pear)


Another Trident Maple


Thank you for any help or advice! Salut, Todd