Hi, Dana: The good news is that you have two healthy trees. The other news is that it is difficult to tell exactly what the problem is with the third, despite your valiant attempt at description. It would seem that this is some sort of fungal infection, either of the tree (and laurel oaks have notoriously thin bark) or roots, possibly resulting in anthracnose. The saw dust could literally be saw dust from a nonrelated insect infestation in dead wood, or it could be spores of some sort. The first option in such cases is usually to clean up both the tree (prune) and site as much as possible and keep it that way. If we were you, though, we would not waste any time in calling in a professional arborist for advice. Thanks for asking, and good luck!
Hi, Dana: The good news is that you have two healthy trees. The other news is that it is difficult to tell exactly what the problem is with the third, despite your valiant attempt at description. It would seem that this is some sort of fungal infection, either of the tree (and laurel oaks have notoriously thin bark) or roots, possibly resulting in anthracnose. The saw dust could literally be saw dust from a nonrelated insect infestation in dead wood, or it could be spores of some sort. The first option in such cases is usually to clean up both the tree (prune) and site as much as possible and keep it that way. If we were you, though, we would not waste any time in calling in a professional arborist for advice. Thanks for asking, and good luck!