It generally appears in late winter to early spring when the temperatures are on the rise. However, it may be seen earlier if conditions are proper for the fungus. Warm, humid weather following a cold spell will cause sporulation of the fungus and subsequent infection. This disease is characterized by brown spots on the petals. These usually enlarge until the entire blossom is blighted.
Infected flowers fall to the ground and the fungus produces hard, resting bodies called sclerotia.
These selerotia may remain under the bush or in the soil or debris for several years. These spores are carried by the wind and cause infection when they land on a flower. Control measures involve the removal and destruction of all fallen blossoms. If all flowers could be picked up every year this would disrupt the life cycle of the fungus. However, this is only effective if you do not live close to other camellia growers as the fungal spores may easily blow from yard to yard.