I am in Fort Worth and we have a Red Oak that we planted almost exactly a year ago (I'd guess its about 15' tall). It has been absolutely great and we've had no problems with it at all. The other day, however, we noticed small spots on pretty much all of its leaves (see pics). Anyone know what could be causing this? Do we need to call an arborist? We are completely new to this and are afraid of losing our trees...we lost some last summer and don't want to go through that again, considering the cost and effort to replace them at that size.
FYI, we have been watering it three times a week all summer according to the tree farm's instructions.
Thanks in advance for any advice you can give.