- Soft rot (Erwinia carotovora or E. aroidae): A soft, mushy, foul-smelling rot of rhizomes or stem bases. Cut out rotted spots before planting. Place rhizomes in separate containers and water individually if possible to reduce disease spread. Use a well-drained growing medium.
- Root rot (Phytophthora or Pythium spp.): Roots are decayed back to the rhizomes.
- Viruses: Small plants, chlorotic foliar streaking, flower distortion. Discard affected plants.
