Question
One of the two main branches on my tibouchina tree died and I had to cut it off.  I noticed the trunk has splotches of a greenish gray crusty stuff all over it, which can be peeled off.  Is this gray mold?  How do I treat it?  I don't want to lose this beautiful mature tree.

Answer
Dear Lynn, There are actually not very many things that can go wrong with the glory tree other than getting too cold (not likely in Florida) or too much moisture which you may have had this year.  Damp soils can lead to mushroom root rot, which could be affecting your tree.  As far as the splotches of greenish gray stuff on the bark, this is a lichen and normally won't bother your tree, but you can pull it off if you want.  Sometimes branches just die, but look for things like wet soil which could indicate a fungus in which case you could treat the soil with a fungicide and try to get the conditions drier (obviously if it is wet from rainfall there is not much you can do), and also look closely on the branches for little holes that could be a sign of borers which can attack any tree.  I have had a lot of people writing in about problems with borers.  Borers come in many types, but they are often big, showy attractive bugs.  If you suspect borers, you can spray with a product from Ferti-Lome called Borer, Bagworm, Tent Caterpillar Spray.  You will probably need to spray several times.  So, my main guesses for what is wrong with your glory tree would be soil fungus from wet conditions, in which case you should spray with a fungicide (Daconil might be good for this) or borers in which you should use the borer spray.  I hope you are able to save your tree.  Please write back if you have further questions.  Good luck, Melissa