Im not sure if you got plumerias, but I have advice on keeping them nice and clean. I have 5 HUGE plumeria trees in my yard that anyone standing around my house can smell easily and I can make leis everyday if I wanted (and have for people visiting). I am talking about the trunk of the plumeria tree is about 8-10 inches in diameter on all of them. Im not sure if this is just a Hawaii thing, but here we get a white cottage cheese looking substance and black spots on the leaves and branches sometimes if not taken care of properly. If you get a sprayer that has a bottle attached to the hose, fill it about a quarter way full of Dawn dish soap, and the rest water. Spray the whole tree down every other day and the white and black stuff will go away. If I am too vague, let me know and ill elaborate more. GL