Causes

• Overwatering is a common cause of root rot in phalanopsis orchids, according to the Missouri Botanical Garden. Plants that receive excessive amounts of water suffer adverse effects because plant roots are deprived of adequate amounts of oxygen.
  
  

Symptoms

• Phalanopsis orchids suffering from root rot exhibit symptoms that include slow growth, shriveled leaves and poor plant health. Orchid roots with root rot disease often appear dark brown and have a mushy consistency.
  
  

Control

• Using water high in soluble salt is not recommended for phalanopsis orchids. Typically, water softeners with high sodium contents cause adverse effects in orchids. To discourage the development of root rot disease, water your orchids in the morning and avoid watering them again until the soil surface is completely dry. Do not let water sit in the bottom of a pot, as this promotes disease development.