Waterlily Crown Rot

The first symptoms are yellowing leaves, which sometimes become mottled. The leaf stems then become soft and blackened, and later break away from the crown. The crown will be soft and gelatinous with black tissue inside and have a vile smell. Remove the plant at once; if this is done early enough, it should not spread to other waterlilies, especially if these are different species or cultivars. If other plants remain unaffected for a few weeks, it is safe to replace the lost plant.