Many foliage plants are susceptible to bacterial diseases, showing typical symptoms of leaf spots, blights, and wilting. Although bacteria are found on the surface of all plant surfaces, certain conditions, such as high humidity, crowding and poor air circulation, may lead them to multiply out of control. Misting plants can also provide a film of water on the leaves where bacteria can multiply.

Unhealthy plants, or those in poor conditions, often become stressed, making them predisposed to bacterial infection. To reduce plant stress, avoid the following conditions:

• Too much, too little, or irregular watering.
• Fluctuating temperatures.
• Low light intensity.
• Poor soil drainage.
• Too large or too small a pot.
• A deficiency or an excess of nutrients.

The most severe and devastating diseases of foliage plants are caused by bacteria belonging to the genera Erwinia and Pseudomonas, which can cause infections such as fireblight and bacterial canker.