I have cork oak seedling where the older leaves (last year's growth) start looking like this:
Though wind resistant, it falls off if slightly touched. Go figure.
But I don't think the plant is in poor condition. The roots are healthy. New buds are popping up and they seem vibrant and vigorous.
Is this condition a normal condition of older oak tree leaves or is it some sort of fungal disease?
Or is it due to over watering issues? I suspected this and I considerably dialed back on the watering and am making sure to check if the soil is quite dry before saturating. Maybe that's why the new leaves are doing okay but the old ones are damaged?