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Nursery News
nursery news  
February 2012
About this newsletter
A new threat to boxwood
Phytophthora ramorum update
Growers Assisted Inspection Program
Crossword puzzle
Please join Listserv, an email notification system
Revised noxious weed quarantine standard
Nursery plant escapee becoming weedy
Quarantine summaries
Helpful links
Holiday and furlough schedule
About this newsletter
Dahlia at nursery, Image courtesy of Lisa Rehms, ODA
The Nursery Newsletter is a semi-annual to annual publication of the Oregon Department of Agriculture and is intended as an aid to anyone involved in the growing and shipping of nursery plants. Through this bulletin, we hope to provide you with the most current shipping information as well as other topical information related to the nursery industry. If you have any suggestions for topics or articles for the next issue, contact Lisa Rehms via e-mail at lrehms@oda.state.or.us
Horticulturists:  Debbie Driesner, Dan Hawks, Lisa Rehms, Eric Reusche, John Ekberg, Karl Puls, Sherree Lewis, Scott Rose, Dennis Magnello, Gary Garth, Bev Clark, Susan Schouten
Gary McAninch, program supervisor; Jan Hedberg, lead horticulturist; Sue Nash, program assistant; Kim Lawson, office specialist; Melissa Lujan, GAIP auditor
Lisa Rehms and Bev Clark, editors
A new threat to boxwood
Boxwood blight, Image courtesy of Karl Puls, ODA
By Lisa Rehms, ODA Horticulturist
A new fungal disease of boxwood was identified in the United States this past year. Cylindrocladium buxicola (syn. C. pseudonaviculatum), commonly known as boxwood blight, was identified on boxwood at a nursery in Washington County, Oregon in December 2011. This is the first known find in the Pacific Northwest. A couple months earlier, the pathogen was found in the eastern United States (October 2011) at nurseries in Surry County, North Carolina and Carroll County, Virginia; and at a residential landscape in Middlesex County, Connecticut. The pathogen was most likely transported on boxwood from nurseries in Europe, where it is known to occur. Boxwood is not native to the United States.
C. buxicola is a fungus of the boxwood family, Buxaceae. Although all boxwood species may be susceptible to blight, American boxwood varieties appear to be particularly vulnerable. Sarcococca, another member of Buxaceae, has also been shown to be susceptible to the fungus.
Symptoms on boxwood include light or dark brown circular leaf spotting and black longitudinal or diamond shaped lesions on stems. Progression of the disease results in defoliation of leaves and an overall straw colored appearance of the plant. Disease transmission is increased in moist environments, making host plants in greenhouses particularly susceptible. The fungus can form resting structures (chlamydospores and microsclerotia) that can survive for years on host organic debris in the soil. Mortality most often occurs in seedlings, but may also take place in older plants, especially if infected with a secondary pathogen.

Please contact your nursery inspector or the Oregon Department of Agriculture if you see any symptoms of boxwood blight (http://oregon.gov/ODA/PLANT/NURSERY/contact_us.shtml). Additional information on boxwood blight can be found online at the following sites:

Phytophthora ramorum update
survey for p. ramorum  
Aaron French surveys a nursery for P. ramorum
By Sherree Lewis, ODA horticulturist/SOD survey coordinator and Jan Hedberg, ODA lead horticulturist

The 2011 Phytophthora ramorum survey season has been completed with the inspection, sampling and testing of host plant material from 628 nursery sites. In addition, horticultural inspection staff completed the inspection of 529 non-host nurseries. Six nurseries were found positive in 2011. All of the positive plants found were either Rhododendron or Camellia. Five of the nurseries have completed all parts of the USDA-APHIS required Confirmed Nursery Protocol with the sixth very near completion.

In 2011 the USDA implemented an additional requirement for some nurseries that had been issued a federal P. ramorum shield. Beginning March 1, 2011, nurseries in Clackamas, Columbia, Lane, Lincoln, Marion, Multnomah, Washington and Yamhill counties and shipping Camellia, Kalmia, Pieris, Rhododendron (including Azalea) and Viburnum are required to provide advance notification of each shipment to destination state’s regulatory officials. State contact information can be found at http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/index.shtml.
Nurseries in the affected counties are required to sign an amendment to their already in place signed compliance agreement, acknowledging the notification requirements. All nurseries with valid federal compliance agreements and located in the affected counties were notified of the additional requirements and provided with an amended agreement to sign and return for federal processing. While most nurseries returned the form, some have not done so yet. They have been contacted several times to remind them of the requirement. If the ODA does not have this document on file, it is possible that the P.ramorum certification for the nursery could be rescinded. Please contact the ODA as soon as possible if uncertain of your certification status. (Jan Hedberg, 503-986-4644)

A survey of 130 Christmas tree fields was conducted for P. ramorum. No positive finds for P. ramorum were detected from the samples taken from Christmas tree fields.

Additional information on SOD regulations:

Growers Assisted Inspection Program
gaip logo  
By Melissa Lujan, Inspection Program Auditor

A Systems Approach – How it Can Help Your Nursery

The Grower Assisted Inspection Program (GAIP) will begin its fifth year in 2012. The volunteer program was developed to help nurseries prevent the introduction and spread of Phytophthora spp. in the Oregon nursery industry using “systems approach” concepts. In a systems approach, the entire nursery system explored from procurement to the final product. By checking all steps during production, potential problems can be found before becoming fully established. Strategies used in the GAIP are not strictly for Phytophthora spp. They can be applied to aid with other pathogens, insects, and even weed control. The following will describe some things you can begin to do at your nursery to ensure you have a clean, healthy final product.

1. Propagation and Procurement
This is the first step to pest control in the nursery. If something is brought to the nursery or becomes contaminated during propagation, problems will continue to snowball if not taken care of properly.
  • Purchase outside material only from sources that are licensed or certified under all applicable state and federal phytosanitary regulations.
  • As soon as new products arrive at the nursery have a trained staff member immediately inspect the material for any signs of disease or pests. If something does not meet your standards do not accept the material. It is your right as a customer to reject suspect material.
  • Notify the shipping nursery or delivery drivers that their vehicles must be clean upon arrival at the nursery. Do not allow drivers to clean out debris at your location.
  • Avoid accepting returned plant material at your nursery. If your nursery does accept returns, quarantine the material away from other material for at least 30 days. Observe for the presence of any pests.
  • Properly train employees on proper sanitation procedures for their tools, work area, vehicles, and themselves while working with plant material. Periodic meetings or posters are a good way to remind employees on the importance of sanitation.
  • Clean tools often and in-between crops with an approved disinfectant. Always follow the label and make sure employees understand the importance of sanitation.
  • Keep the work area clean and free of debris. Old debris is a great habitat for pathogens and insects.
  • If vehicles or equipment are shared throughout the nursery, clean the undercarriage and tires before heading into the propagation area.
  • Provide employees with soap, shoe brushes, and any other items they may need to clean their personal equipment.
2. Water Management

Irrigation staff needs to be properly trained to understand plant water needs. Over-watering plant material can provide the perfect environment for pathogens to thrive.
  • Arrange the nursery layout to reflect plant water needs (i.e. water loving and xeric (dry) plants should be grouped separately). Watering correctly will provide healthier plants, reduce overall plant disease and decrease utility bills.
  • Pay attention to weather reports and adjust irrigation schedules to reflect the conditions. Monitor by using a home weather station, online sources, local news, or rain gauges to measure the actual amount of rainfall or irrigation water. Be sure to empty the gauges in-between rain events/irrigation cycles to ensure accurate readings.
  • Do not allow areas of standing water to become established. Use gravel, drain tiles, or re-grade the nursery beds directing excess water away from plant material.
  • Give plants adequate spacing. Airflow will allow any excess water the chance to evaporate off the leaves.
  • Install sprinklers that allow you to control the direction of the impact head or add ball valves to the line. By installing these you can control where and when beds will be watered.
3. Used Containers

Reusing old containers is a risky business. Although it may appear that a container is “clean”, remember that pathogens are microscopic and can hang around on the inside.
If new material is planted into a contaminated container, a new disease cycle can begin.
If you choose to reuse containers, make sure that they have been properly sanitized before re-use.
Sanitation options include:
  • Chemical use. It is very important that the minimum amount of time required for the chemical is reached (follow all labels). Before placing into the disinfectant wash off any debris remaining in the container. This is because many chemicals become de-activated when coming in contact with organic matter. The solution is also less effective when full of debris.
  • Steam aeration has been shown to be very effective in the removal of pathogens and even weed seeds. Most plant pathogens need a minimum of 140 degrees F for a minimum of 30 minutes, while weed seeds require higher temperatures. It is important to ensure the core temperature meets the required temperature and time in order to be effective.
  • Hot water baths may be used to treat used containers. Containers must be fully submerged and the temperature needs to reach at least 180 degrees F for a minimum of 30 minutes to be effective.
More information on chemicals and a temperature chart can be found in Chapter 7 of the free OAN Safe Procurement and Production Manual. http://oan.org/associations/4440/files/pdf/SafeProduction.pdf
4. Native Soil and Potting Media Storage
  • Store potting media on a clean, well-drained, non-porous surface. Research has shown that potting media can become contaminated from being placed on native soil.
  • Place potting media storage areas away from areas of standing water, high traffic areas, and away from cull piles.
  • Clean shared nursery equipment before entering potting media area.
  • If potting media has been sitting around for a long time it is not a bad idea to have it tested to ensure soil has not become infested with any pathogens.
  • Know where your source originates. Purchase from sources that can supply you with the origin of the soil.
  • If you purchase composted material make sure the supplier has followed proper composting procedures.
These are just a few of things you can do to prevent pathogens in your nursery. Remember, you hold the key to what happens in your nursery. If you have further questions about how systems approach practices can help you or are interested in joining the GAIP please contact Melissa Lujan at 503-510-5529 or send an email to mlujan@oda.state.or.us.

Additional sources:

OAN Safe Procurement and Production Manual http://oan.org/associations/4440/files/pdf/SafeProduction.pdf

OSU PhytophthoraOnline Course: Training for Nursery Growers


Crossword puzzle
Nursery Puzzler by Gary Garth, ODA Horticulturist

 Nursery Puzzler

Please join Listserv, an email notification system
The Oregon Department of Agriculture (ODA) started an email listserv in 2011, to more rapidly communicate important information to nursery license holders and others interested in the nursery program. If you haven’t joined the e-mail listserv, and would like to, simply send an e-mail to: NurseryList-subscribe@oda.state.or.us

You will receive an e-mail message confirming your subscription.
Revised noxious weed quarantine standard
Hydrilla, Image courtesy of Vic Ramey, University of Florida
By Bev Clark, ODA Horticulturist
During the 2009 legislative session, Oregon Revised Statutes pertaining to the Noxious Weed Laws were consolidated and updated in ORS 569-350. Included in this rewrite is new authority for ODA to address noxious weeds as a public nuisance in administrative rule. Over the past year, cooperators and the public were consulted to update the Noxious Weed Quarantine. The process of drafting and developing rule was completed in 2011 and provide more authority for ODA and county noxious weed control programs to address “A” listed noxious weeds under OAR 603-052-1200. Through the administrative rule process, ODA has incorporated new standards. The following is a summary of the updates.

In summary, a quarantine is established for State Listed Noxious Weeds that prohibits the intentional entry into the state and propagation, transportation, purchase or sale within Oregon. The quarantine outlines how “A” and “B” weeds are to be addressed. It also grants new authority to the State Noxious Weed Control Program to enter onto lands for the purpose of carrying out noxious weed control activities, requires mandatory control of “A” listed weeds, and allows for civil penalty to be imposed for violation of the rule.

Control of “A” listed weeds is the highest priority and the primary goal is to prevent their introduction and permanent establishment in Oregon. This is accomplished through exclusion, early detection, and rapid response activities. If introduced, and eradication is not feasible, the secondary goal is containment to prevent widespread establishment.

The goal of “B” weed management is prevention and control of new infestations based on ODA priorities, current distribution, and availability of funds to address such issues. ODA may advise or assist county programs and cooperators with control of “B” weeds. In some cases, “B” listed weeds may be treated in the same manner as “A” weeds when they are found in a part of the state where they are not widely established or are not known to occur.

For more detailed information reference: Quarantine; Noxious Weeds (603-052-1200)
The Oregon noxious weed quarantine list can be found at: http://oregon.gov/ODA/PLANT/WEEDS/lists.shtm

Nursery plant escapee becoming weedy
Yellow archangel
By Bev Clark, ODA Horticulturist
Another nursery grown plant is threatening to overrun our urban and wildland areas. The culprit of this all too familiar story is Yellow archangel, Lamiastrum galeobdolon. Yellow archangel is native to Europe and Asia and was introduced to the United States as an ornamental plant. It has spread to forest habitats and natural areas through dumping of yard waste or intentional plantings.
Yellow archangel is a fast-growing, herbaceous perennial that spreads by stem fragments, rooting at nodes and by seed. It can escape from garden settings and form dense patches that outcompete native plant species. Yellow archangel can tolerate a wide range of conditions, from full sun to full shade. It is now found in ravines, greenbelts and forested parks throughout the Pacific Northwest.
Lamiastrum galeobdolon has been placed on the watch list in Oregon, and the Oregon Weed Board is considering listing it as a noxious weed. Currently Yellow archangel is listed as a non-regulated Class B noxious weed in King County, Washington. Control is recommended but not required.

Quarantine summaries
The ODA has certain quarantines or regulations regarding nursery and Christmas tree plant material being exported or imported to and from the state. Regulations of plant material exported out of Oregon to other states is summarized in the export quarantine. The import quarantine provides a summary of Oregon and federal plant quarantines for plant material imported into and within the state.

Helpful links
Oregon Department of Agriculture

Oregon State University

United States Department of Agriculture, Animal and Plant Health Inspection Serivce

National Plant Board

Pacific Northwest Management Handbooks Online

Holiday and furlough schedule

February 20, Monday  Presidents Day
March 23, Friday
May 25, Friday  Furlough
May 28, Monday
 Memorial Day
July 4, Wednesday
 Independence Day
August 17, Friday  Furlough
September 3, Monday  Labor Day
October 19, Friday  Furlough
November 12, Monday
 Veterans Day
November 22, Thursday  Thanksgiving Day
November 23, Friday
December 25, Tuesday
 Christmas Day