Question
I live along the Florida Panhamdle.  Lately, the wax myrtles in our neighborhood--some planted by our landscaper, but the ones that have grown naturally have developed a sweet honey like odor and are turning black.  One of the affected lots has cleared all the plants, but this seems to be spreading.  what is it and how do we control this problem.  Our neighborhood landscape plan consists of mostly native vegetation.

Answer
The first thing I would look for is some kind of insect on the underside of the leaves.  Scale, Aphids and Whiteflies all produce honeydew when the feed and this in turn attracts a black sooty mold that grows on the honeydew on the leaf surface.  If you find this to be the case, an insecticide is going to be necessary to get rid of the bugs.  Bayer Advanced Tree and Shrub Insecticide is a good product for this purpose.  It is a systemic insecticide that is mixed with water and then poured on the soil around the plant.  The bugs are killed within a week or two and the product protects the plant for up to 6-8 months.  Let me know if you find this to not be your case and I will think of other possibilities.  Good Luck.