A widespread plant disease caused by the fungus, sclerotium rolfsii. The fungus decays or destroys the leaf and stem bases, bulbs and rhizomes.
Plants grown from rhizomes die starting at the leaf tips and progressing ever downward.
Leaf bases may be dry and brown, or rotted. Irises grown from bulbs will be stunted, yellowed and die prematurely. Leaves and stems are rotted at the soil level and bulbs will be soft and crumbly. White fungal strands may cover the crown and soil in both types of plants, and tan to red or brownish pellets will cover the infected plant tissue and be present on nearby soil. Crown rot is spread by moving diseased transplants, infested soil and water and tool contact with contaminated species.