Oily black stuff on Crape Myrtle
I have a couple of pink Crape Myrtle trees, and their leaves have this black oily film on them, and the branches also have this, plus have white spots too. I've had this before, last year too. Is this a big deal?
I have a white crape myrtle nearby that doesnt have this problem. It has grown much larger than these 2 smaller trees. Anyone seen this before?