Nursery and Christmas Tree

Sudden oak death (SOD), Phytophthora ramorum, is a federally quarantined pathogen that has caused widespread dieback of tanoak and other oak species in forested areas of 15 counties in California and parts of Curry County, Oregon. It has also been found infecting horticultural plants at nurseries in California, Oregon, and Washington.

History of SOD in Oregon's nurseries

Sudden oak death (SOD) was first found in an Oregon nursery in 2003. It has been detected in limited nursery sites every year since then. When detected, the nursery must complete all requirements of the USDA confirmed nursery protocol.

Requirements include the following:

  • Immediate quarantine of positive nursery
  • Delimitation surveys to assess the extent of the infection
  • Destruction of all infected plant material
  • Trace survey inspections of all host material shipped and received by the nursery for previous 6 months
  • Survey monitoring by inspection and sampling for the next 3 years

While more than 135 plants have been proven to be hosts of SOD, the following five are detected most often:

  • Camellia
  • Pieris
  • Rhododendron
  • Viburnum
  • Kalmia
SOD regulations


Oregon nurseries shipping plants out of state that are located within the quarantine area of Curry County or that have been found positive since March 31, 2011, are required to meet requirements of the USDA Federal Order DA-2014-02.

Oregon nurseries approved to ship nursery stock out of state need to be listed on the Oregon Department of Agriculture website. Nurseries listed there are required to be inspected for presence of SOD annually. These nurseries are not required to use a USDA Phytophthora ramorum certification shield with their shipments. 


Recipients of tree and shrub nursery stock imported into Oregon are required to notify ODA.


APHIS list of regulated hosts and plants proven or associated with Phytophthora ramorum


California Oak Mortality Task Force


Curry County sudden oak death quarantine area

Map of sudden oak death quarantine boundaries in Curry County. Document

Oregon Public Broadcasting: Sudden Oak Death


Phytophthora ramorum a guide for Oregon nurseries

Phytophthora ramorum a guide for Oregon nurseries Document

Phytophthora ramorum: Sudden Oak Death

USDA Animal and Plant Health Inspection Service (APHIS)

Phytophthora ramorum: Sudden Oak Death regulations


Plant Plague: Sudden Oak Death

Bay area public broadcasting TV station KQED video story. Website

Safe procurement and production manual

P. ramorum — Safe procurement and production manual for nurseries. Document

Sudden Oak Death and Phytophthora ramorum: A summary of the literature





Main Office
Nursery & Christmas Tree
635 Capitol St NE
Salem, OR 97301
Phone: 503-986-4644
Fax: 503-986-4786