African violets are easily the most popular flowering houseplants in America.
Their popularity arises from the fact that they are easy to grow and can bloom for 10 to 12 months of the year. They commonly have disease and pest problems, but most of these can be avoided by following the recommended cultural practices to keep plants healthy as described in HGIC 1550, African Violet . The older leaves droop, and the younger leaves in the center of the plant appear stunted, turn black and die. The fungi Pythium species and Phytophthora species can cause this problem, especially when plants are watered excessively, have poor drainage, or are planted too deeply. Any of these conditions can contribute to rotting of the crown and roots.