Plant Health Problems
Diseases caused by Fungi:

Root rot, Rhizoctonia sp.
Leaves gradually turn yellow, brown, and drop. Symptoms often start on the lower leaves and progress up the plant. Affected plants often have poor vigor and show non-specific symptoms of general decline.

Control can be achieved by using a sterile potting mix and clean pots. It is also helpful to avoid overfertilizing and overwatering, especially in the crown area of the plant. It is important to never let the plant sit in standing water. Highly symptomatic plants can be rogued and removed since recovery is unlikely.

Diseases caused by Bacteria:

Bacterial leaf spot, Erwinia spp.
Tiny, water-soaked areas develop on the leaves. These areas expand into tan to blackened lesions. When the bacteria move into the petioles, the leaf collapses and often drops. Infection can spread very quickly and affected plants often develop an unpleasant, fishy odor.

Control can be achieved by removing the infected leaves as soon as symptoms appear. Since the bacteria are easily spread through handling and splashing water, care should be taken when handling the plants. It is prudent to destroy severely infected plants since recovery is unlikely. This also helps to eliminate sources of the bacterium and subsequent spread to healthy plants.

Insect Problems:

See Houseplants.