Question
I have a beautiful Ming tree that has developed a sticky leaves and stems in some areas.  I don't see any bugs and can't imagine what is causing this.

Answer
Dear Tomme, I can almost guarantee that your Ming tree has scale.  Scale is a non-moving insect that lives under a hard shell, and since the trunk of the Ming is a bit bumpy it is often overlooked.  I would spray the entire tree with horticultural oil (SunSpray is my favorite) to remove the scale.  Let the tree dry in a bright warm area.  You will have to spray several times about 5 to 7 days apart to completely remove them.  You will know you are successful when the scale starts falling off and the tree is no longer sticky.  Good luck, Melissa