Root rot often associated with over watering and water moulds florishing
Roots soften and die back - usually associate with a foal smell.
Wilting, yellow or sparse foliage
Improving soil drainage can greatly reduce the risk of plants succumbing to the disease.
Where the disease is new or localised in the garden, affected plants should be destroyed and the soil from the root-run replaced with fresh topsoil. Replanting should be done with less susceptible species.