University of Maryland Extension

Bacterial Leaf Spots of Houseplants

bacterial spot dracaena

  • There are several species of bacteria that attack houseplants.
  • Some of these bacterial infections become systemic throughout the plant while others will remain as localized lesions.
  • Bacterial disease symptoms range from black to brown, often watery leaf spots or lesions to total collapse of the tissue.
  • Collapsed tissues usually are soft and mushy with a rotten smell to them.
  • Leaf symptoms will often be observed between the veins and may be contained between leaf veins and appear angular or V-shaped.
  • Some plants will characteristically develop lesions along the leaf margins where the bacteria enter through hydathodes (small openings along the leaf margins). Often these infections will cause leaf drop.
  • Other symptoms may include yellow margins around leaf lesions, small blister like spots that run together, or spots where the center falls out.

Management Strategies 

  • There are no cures for systemically infected plants and these plants should be discarded.
  • Individual leaves with spots can be picked off and destroyed.
  • Any method that will lower the humidity, decrease leaf wetness or increase air circulation will help to lessen the chances of infection.
  • Watering should be done early in the day to allow leaf surfaces time to dry quickly.
  • Space plants so that air can circulate between them to help reduce moisture.
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