QuestionI have an old 40 ft magnolia tree. Had some leaf spots and treated with copper solution and epson salts. Noted bark on large trunk has some vertical splits/? descaling. No obvious insects. Do I treat with oil??
AnswerNo I would not treat with anything. Sounds like just normal bark sluffing. As long as the tree is healthy looking and the foliage is full the tree is fine. If you see any sawdust or holes in the bark then I would spray the area with an insecticide called Merit or Onyx. This will kill any borer type insect that is attacking the trunk. But I would not spray unless I saw signs of damage.
