Sudden Oak Death (SOD) is a disease caused by the pathogen Phytophthora ramorum. Despite its name, this pathogen attacks over 100 species of vines, shrubs, herbaceous plants, trees, and even ferns. It attacks the foliage of some plant species, and the trunk of others. When SOD attacks the foliage, the disease is called “ramorum blight”, and is not considered fatal. This condition is still dangerous, because plants with ramorum blight are the ones who spread SOD around. When SOD attacks the trunk or stem of plants, it is usually fatal.
SOD has been found in nurseries throughout Europe and in California, Oregon, Washington, and British Columbia. In the wild it has been found in California, Oregon, the Netherlands, and the United Kingdom. No one knows where this pathogen came from. It is not native to any of the areas where it is currently found, and no native range has been found to date.
An isolated outbreak was found in 2004 in a nursery in the Tidewater area of Virginia. Quick action was taken and the disease did not spread. Monitoring is ongoing at nurseries throughout the state, so that hopefully any new infestations will be discovered and eradicated.
Symptoms vary by plant species, and positive identification is only possible through laboratory testing.
To learn more about this potential plant pest, click here