I live in So Cal temperatures arrange from ninety to a hundred degrees summer I have fifteen or so established plumeria. Ten of them are splitting and getting weird callous or brown patches in middle of branch. I think I am having a problem with rust it’s getting bad. Minor problem w/black tipped leaf curl. I have been using need oil every two weeks and fertilizing regularly since April. I have two which have not flowered. On the largest of my plumeria they are getting slightly soft at the top branches.
I can post more pictures if needed.
Thank you