Answer: Michelia is a member of the magnolia family and as such is susceptible to the same fungal leaf blights and leaf spots as magnolia. Plants under stress are most likely to develop insect and disease problems. Stress can be a result of transplanting, exposure to too much or too little sunshine, over- or under-watering, or too much fertilizer. Your first course of action should be to take a specimen of the problem to your local Cooperative Extension office or Master Gardener Clinic to get a positive identification of the problem. Once the problem has been diagnosed, you'll be given some control recommendations. Phone 619-694-2845 for the location of your nearest diagnostic clinic.
Best wishes with your trees!
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