The fungus can survive between the scales of the bulb, particularly in the neck region, and infects the new leaves as they emerge in spring. It does not usually cause decay in narcissus bulbs, although bulb rotting has been recorded on some of the other hosts. The fungus can also survive on old leaf debris.
Microscopic spores produced in the fruiting bodies on affected aerial parts of the plant are splashed by rain droplets and can lead to further spread of the disease, both on the affected plant and on to neighbouring plants. The disease develops most rapidly at temperatures of 15-20°C, but can be active down to 5°C.
On Hippeastrum, the fungus causes a disease known as red spot. Bright red spots develop on the bulb, and the affected areas become sunken and soft as they enlarge. Red spots and streaks also develop on the leaves and flower stalks.