Identification

• White spots usually are mildew, which appears as a fuzzy white outgrowth. If the white spots are sunken into the leaves, the cause may be red mite infestation. If you suspect red mites, look for small webs within the branches of the banana shrub.
  
  

Significance

• White spots on the banana shrub's leaves are unsightly and lethal. Mildew growth prevents leaves from photosynthesizing, depriving the plant of nutrients. Red spider mites feed on banana leaves and gradually kill the plant.
  
  

Solution

• Mildew-infested leaves should be pruned immediately. Though mildew is most visible on the surface, it penetrates deep into the leaf and can spread if the leaf is not clipped off. Red spider mites can be killed with pesticides and the damaged leaves will gradually recover.
  
  

Prevention

• Spray the banana shrub with fungicide to prevent future mildew. General purpose insecticides prevent red spider mite infestation.