My oxydendrum has some sort of leaf spot, on all leaves. It never completely greened out this year, or filled out with foilage- all the leaves it has are a pale green/pink. Now it's turning to red leaves and loosing them. I don't think it's cosmetic, especially since the foliage is so sparse, staring right in the spring. Also, most of the very tiny branches coming off a larger branch are dead. Please help!