HRI & OAN Boxwood Health Workshop Recap

Over a quarter of all boxwood (the #1 broadleaf evergreen shrub!) production in the U.S. occurs in either Oregon, California, or Washington. A handful of pests challenge boxwood production and landscape management, but boxwood blight has emerged as a significant threat. This disease is even more troublesome in the PNW since symptoms appear to be more subtle as compared with other regions.

HRI, OAN, and AmericanHort hosted a one-day workshop in Oregon to talk about boxwood health. Specific topics included:

  • The latest updates on cultivar testing and control strategies of boxwood blight,
  • Insights from a major boxwood producer in the heart of boxwood blight country on how to start clean and stay clean
  • An overview of nursery production surveys for boxwood blight in Oregon
  • An update on APHIS efforts to prevent introduction of box tree moth to the US.

Representatives from Oregon Department of Agriculture were be on hand to discuss the Oregon boxwood cleanliness program.


Presentation materials are available for download from the following workshop sessions:

Sanitation for boxwood blight management, (PowerPoint) Dr. Fulya Baysal-Gurel, Research Assistant Professor, Tennessee State University
The session addressed 1) why you should use sanitation practices at boxwood production and 2) improved boxwood blight sanitation/hygiene practices through research results.

Cultivar Resistance (PDF), Dr. Jim LaMondia, Connecticut Agricultural Experiment Station
The potential for boxwood cultivar resistance/susceptibility and fungicide programs for management of blight.

First year scouting insights from the Oregon boxwood blight survey (PDF), Dr. Jerry Weiland, USDA ARS
This presentation covered the range of boxwood blight symptoms that growers can expect to see, some other common diseases that may look similar, scouting strategies for detecting boxwood blight, and some common risks that may lead to explosive boxwood blight outbreaks, spreading the pathogen, or make detection difficult. Also included: a summary of the cultivars affected by boxwood blight.

Boxwood Blight - A Managed Disease (PDF), Bennett Sauders, Saunders Brothers Nursery
After the record rainfall in 2018, Boxwood Blight became a common disease active in many gardens in the mid-Atlantic area of the United States. Along with the increased incidence of Box Blight, researchers have recently identified many commonsense ways to reduce the incidence of Box Blight at the nursery level. Bennett explained Saunders Brothers’ Nursery “one two punch” of 1) BMP’s and 2) more tolerant cultivars to greatly reduce the chance of introduction and severity of Boxwood Blight.

Boxwood Blight Cleanliness Program (PDF), Chris Benemann, Oregon Department of Agriculture
In 2011, the Oregon Department of Agriculture created the voluntary Cleanliness Program In response to concerns of boxwood blight spreading among Oregon nurseries. The program emphasizes the working relationship between a nursery and their ODA inspector to effectively scout for the disease.

Does the arid Mediterranean climate have an impact on Boxwood blight infection and symptom severity? (PDF), Karen Suslow, Program Manager & Principle Investigator, National Ornamental Research Site at Dominican University CA (NORS-DUC)

Cydalima perspectalis Box Tree Moth – An APHIS Overview (PDF), Judy Macias, Assistant Trade Director, Phytosanitary Issues Management, Plant Protection & Quarantine
APHIS provided an overview of Box Tree Moth (Cydalima perspectalis), including its general biology (description, life cycle, distribution and hosts), and discussed current and pending restrictions to prevent its introduction into the United States.

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