Phytophthora ramorum regulations for nursery growers

Phytophthora ramorum is a serious pathogen of many ornamental and native plants grown in Oregon. The regulations described in this section have been designed to help prevent the spread of this pathogen. All Oregon nurseries should take the regulations very seriously. If your nursery is found with Phytophthora ramorum plant material, the USDA and the ODA will work with you to meet all regulations to eliminate the pathogen from your nursery, and to limit its spread to other nurseries. They will also recommend best management practices that will help prevent disease from occurring again.

Many details of regulations discussed in this section will change frequently. Please revisit website references regularly to obtain the most current information.

History of Phytophthora ramorum Federal Order and the follow-up Federal Interim Rule

On January 10, 2005, a USDA Federal Order went into effect, regulating the movement of nursery stock from Oregon, California, and Washington nurseries. This rule has been updated several times since 2005, the latest being January 10, 2014.

The Animal and Plant Health Inspection Service (APHIS) has revised the P. ramorum domestic quarantine regulations relieving and/or imposing regulatory requirements for the interstate movement of host nursery stock from nurseries located in the regulated and quarantine areas in California, Oregon, and Washington. In addition, APHIS is defining regulatory requirements for nurseries in areas of the United States and its Territories outside the regulated or quarantined areas that test positive for P. ramorum and that wish to move regulated, restricted, or associated P. ramorum host articles interstate. These actions went into effect March 31, 2014.  In Oregon, a portion of Curry County is also under federal quarantine because P. ramorum has been found in the natural landscape.

Phytophthora ramorum Domestic Quarantine Regulatory Requirements

Host and Associated Host (HAP) List

More than 100 species are on the host and associated plant list. Plants on either list may be regulated at the genus level. A complete list of host and associated host nursery stock is on the USDA website.

Specific Requirements of the APHIS Revision DA-2014-02

For nurseries in the regulated areas of California, Oregon, and Washington: the revised regulations apply to nurseries shipping P. ramorum host plants interstate with the requirements based on the last time P. ramorum was detected at the nursery (March 31, 2011).

  1. If a nursery previously found positive for P. ramorum decides they no longer wish to ship plant material out of state, they can “opt out” of the federal program.  They will not be issued a federal certification shield and will not be included on the list of nurseries allowed to ship out of state, which is posted on the ODA website.  They will continue to be inspected annually by ODA following ODA inspection and sampling protocol.  If P. ramorum is detected on the nursery, ODA will require that the federal Confirmed Nursery Protocol (CNP) be completed.  The nursery will not be allowed to ship plant material until the protocol has been completed.
  2.  If P. ramorum has not been detected in a nursery on or after March 31, 2011, and the nursery is located in a P. ramorum-regulated area, the nursery is no longer required to be inspected, sampled, and certified by the USDA-APHIS in order to ship regulated and associated host plants interstate.  However, the nursery will still be subject to an annual, general inspection for state licensing.
  3. If P. ramorum has been detected in a nursery on or after March 31, 2011, the nursery must be inspected, sampled according to an enhanced protocol, and certified by the USDA-APHIS in order to ship regulated and associated articles interstate.  This certification includes signing a compliance agreement and agreeing to follow all of the requirements of the Federal Order.  Regulatory samples will be taken from host plants, standing water, drainage water, irrigation water, growing media, cull pile, and any other articles designated by the inspector as a possible source of P. ramorum inoculum.  The purpose is to better detect P. ramorum if it is present on the nursery site.
  • If any sample is positive for P. ramorum and the nursery wants to ship HAP interstate, the nursery must enter into a compliance agreement with USDA-APHIS. In the compliance agreement, the nursery must agree to address sources of P. ramorum identified during nursery inspection in order to prevent pathogen spread through interstate movement of HAP.  To retain interstate shipping status, all critical control points (CCPs) identified by USDA-APHIS must be addressed by mitigation measures detailed in the compliance agreement. Nurseries under compliance will be issued a uniquely numbered official certification shield.  A copy of this certificate must accompany each shipment of HAP material.
  • If all samples test negative for P. ramorum, the nursery may ship all HAP interstate under a certificate  (federal shield) pursuant to the current regulations of 7CFR 301.92-5(b).  If all samples obtained from the nursery test negative for P. ramorum for three consecutive years from the effective date of the revised Federal Order or from the last time P. ramorum was detected in the nursery, and the nursery is located in a regulated area, the nursery will be relieved of all Federal regulatory requirements for the interstate shipments of HAP following corroboration of their test results.
  • The nursery should maintain records of all incoming and outgoing shipments of host and associated host plants (HAP)  for at least 2-years.  Records should include species and variety, origins of incoming shipments, and destinations of outgoing shipments.

The Oregon Department of Agriculture (ODA) is required to maintain a list of nurseries who ship nursery stock out of state and who are at least annually inspected for the presence of P. ramorum.  The current list “Oregon Nurseries Approved to Ship Nursery Stock Out of State (Phytophthora ramorum) “ can be found on the ODA website.  Contact ODA at 503-986-4644 if you have questions.


Nursery certification is provided only after all requirements of the inspection and sampling protocols have been met and a compliance agreement outlining all additional growing and shipping requirements has been signed.  A federal shield with a unique identification number will be issued to the nursery.  A copy of this shield must accompany each shipment of host plant material shipped.

High-risk Plant Material

Phytophthora ramorum has been found most often on Rhododendron, Viburnum, Kalmia, Pieris and Camellia in nurseries.  During the required nursery inspections, symptomatic samples may be taken for laboratory analysis.

ODA Notification of Shipments Received

All Oregon nurseries are required to notify ODA’s Plant Division of tree and shrub nursery stock imported into Oregon from any out-of-state source within two days of receipt. This information assists ODA personnel in monitoring Phytophthora ramorum host material imported to Oregon as well as plant material of other quarantine concern. Notification can be via mail, fax, or e-mail to:

Nursery Program Supervisor, Plant Division
Oregon Department of Agriculture
635 Capitol St. NE
Salem, OR 97301
fax 503-986-4564

If Detected

If Phytophthora ramorum is detected in your nursery, the federal Confirmed Nursery Protocol (version 8.2 August 6, 2014) will be initiated immediately.

The goal of this protocol is to ensure that any infestations of this serious pathogen are found and completely eradicated.

The Confirmed Nursery Protocol has several parts:

Communicate and Notify

Federal or state officials will notify you as soon as they determined that Phytophthora ramorum has been found at your nursery. An official "Emergency Action Notice" will be issued by the USDA. This document will outline the actions that you must follow. A copy of the Confirmed Nursery Protocol and a current host list will be provided for reference.

Trace Back and Trace Forward information

Secure the Nursery

The requirements of the USDA-issued "Emergency Action Notice" must be strictly followed.

  • All HAP genera in the nursery will be placed under a hold order. No shipping or movement of the stock from or around the nursery will be allowed until all HAP, water, soil, and/or potting media have been inspected, sampled, and tested for presence of Phytophthora ramorum (delimitation survey). All plants in the known infested block will be placed on hold until the delimitation survey has determined the boundaries of the infection block. Access to this block will be limited to authorized personnel only. Strict sanitation procedures such as washing and disinfecting all boots, equipment, and vehicles entering the area will be in place to ensure that Phytophthora ramorum does not spread.

  • Cull piles or plant dumps will be secured until all testing is completed.
  • Equipment used on the nursery site will be disinfected before it is moved off the site.

Survey the Nursery

  • All HAP plants held for sale or propagation in the nursery, including landscape plants not for sale, will be inspected for Phytophthora ramorum symptoms. Samples will be collected for testing if visual symptoms are found.
  • Plants to be destroyed will be identified when the diagnostic results from the survey have been reported.
  • A destruction block will be established by flagging the perimeter of each contiguous growing area or block where an infected plant is found until there is a 2-meter (6.5-foot) break of either no plants or no HAP material.
  • Based upon survey results, plants will be held in quarantine for 90 days.
  • A 90-day quarantine period of the quarantine block will start when the delimitation survey is complete.
  • Samples of soil and water will be taken for laboratory analysis. Samples of potting media will be taken if applicable.
  • Cull and compost piles will be inspected and sampled.
  • A survey concentrating on HAP plants located within 100 meters (325 feet) of the perimeter of the infested nursery will take place. All plants with suspicious symptoms will be sampled.
  • The survey and delimitation will be completed as soon as possible. It may take up to one week to complete. Negative laboratory results are required before any part of the nursery can be released from hold. This could take several weeks to complete.

Disinfestation of the Nursery

  • All HAP material to be eliminated will be destroyed by:
    • Incineration (burning to ash), or
    • Deep burial (double bagging in 2-millimeter plastic and buried at least 2 meters (6.5 feet) deep), or
    • Steam sterilization at 212°F (100°C) for 30 minutes followed by burial in a landfill
  • Nonporous surfaces will be disinfected with a registered and approved disinfectant.
  • Contaminated soil and water will be treated and retested as the Certified Nursery Protocol specifies.
  • Biosecurity measures developed by an ODA/USDA Nursery team will be required. These may include: training nursery personnel to look for signs of Phytophthora ramorum; cleaning all soil off vehicles regularly, cleaning all soil off equipment, and tools regularly; controlling access to high-risk areas; wearing protective boots and gloves that can be decontaminated; and using only new or sanitized pots. These best management practices (BMPs) will continue until the nursery has been found negative for three consecutive years.

  •  Other BMPs may include:
    • A regulatory inspection and sampling of all HAP material twice a year and baiting water runoff for Phytophthora ramorum.
    • Additional soil samples taken 45 days after implementation of the Certified Nursery Protocol and then again as required.
    • Removal and destruction of fallen leaves and plant debris from pots or soil around Rhododendron and Camellia plants regularly.
    • Regular nursery inspection by trained nursery personnel of all host plants as they arrive at the nursery.
    • A 2-year preshipment notification to the office of the State Plant Regulatory Official of all shipments containing any plants in the genera Rhododendron, Camellia, Viburnum, Pieris, and Kalmia.