Hello. I just spoke.with one of your master gardeners(ellen/very pleasant) and she suggested i post some pics. I have 9 golden beech in the back yard close.to the fence. They are 4 years old and have been growing well. I water for.about 1min per tree about 3 times per week. This year 3.of the trees appear to have been turning yellow/brown around the leaf rim. Mostly the bottom.half of the tree. Not.sure.whats going on. The trees.in the backyard are easterly direction so by 4:30 get no.more sun.
Thanks for your kind words about our volunteer!
Now, the first image you provided seemed to match Acalitus Stenaspis mite damage, but that is a pest in Europe primarily. However, the additional pictures you provided appear to show dark stripes forming on the leaves, which might indicate BLD, that is, Beech Leaf Disease. It is a serious disease, also caused by a leaf-eating, microscopic worm-like nematode, Litylenchus crenatae ssp. Mcannia. Please review this BLD information: