Boxwood Blight Knowledge Center

Diagnostic Aids & Management Strategies

Blight Symptoms

Boxwood

Pachysandra

Sweet Box

Boxwood Blight Forecasting App & Push Notification

Scouting, Diagnostic Guides & Tools

Castroagudín, V., Yang, X., Daughtrey, M., Luster, D., Pscheidt, J., Weiland, J., and Crouch, J. 2020. Boxwood blight disease: A diagnostic guide. Plant Health Progress 21:291-300. https://doi.org/10.1094/PHP-06-20-0053-DG

Singh, R., and Doyle, V. P. 2017. Boxwood dieback caused by Colletotrichum theobromicola: a diagnostic guide. Plant Health Progress 18:174-180. https://doi.org/10.1094/PHP-04-17-0024-DG

Weiland, J. and Pscheidt, J. 2020. Scouting for boxwood blight. Digger (March 2020 Issue):25-28
Click here to view the PDF

Yang, X., Castroagudin, V., Daughtrey, M., Loyd, A., Weiland, J., Shishkoff, N., Baysal-Gurel, F., Santamaria, L., Salgado-Salazer, C., LaMondia, J., Crouch, J., and Luster, D. 2021. A diagnostic guide for Volutella blight affecting Buxaceae. Plant Health Progress. Published online at https://doi.org/10.1094/PHP-02-21-0052-DG

Integrated Disease Management

Pscheidt, J. 2024. Boxwood (Buxus spp.) – boxwood blight. Online at The 2024 Pacific Northwest Plant Disease Management Handbook. 


Boxwood Blight Resistance

NewGen Boxwood - Click Here

Better Boxwood - Click Here

Star Roses and Plants Boxwoods - Click Here

Hong, C. X. 2023. Building health into boxwood crops and plantings by making informed cultivar selection. Plant Health Progress (open access)

Brand, T., Beltz, H., Ehsen, B., Adhikari, U., Daughtrey, M. L., Luster, D. G., Kong, P., and Hong, C. X.  2023. Multi-year field plantings evaluating boxwood cultivars for susceptibility to the blight pathogens (Calonectria spp.) in Northern Germany. Plant Disease 107:713-719 (open access)

Kramer, M., Guo, Y. H., and Pooler, M. 2020. Ranking resistance of Buxus cultivars to boxwood blight. Journal of Environmental Horticulture 38(2):50-55 (open access)

Yoder, K. S., Dunn, R. A., Saunders, J. B., Mays, T. R., Yanny, M. D., Hong, C. X., and Scoggins, H. L. 2022. Field performance of Buxus cultivars and selections against boxwood leafminer and boxwood blight. Journal of Environmental Horticulture 40(4):129-142 (open access)

Omolehin, O., Keller, J., Gouker, F., Daughtrey, M. L., Luster, D. G., Pscheidt, J., and Hong, C. X. 2022. Combating an invasive boxwood pathogen – Calonectria pseudonaviculata in the United States by shifting production to more resistant cultivars. Plant Disease. Published online as First Look at https://doi.org/10.1094/PDIS-09-22-2124-RE

Richardson, P. A., Daughtrey, M., and Hong, C. X. 2020. Indications of susceptibility to Calonectria pseudonavicualata in some common groundcovers and boxwood companion plants. Plant Disease 104:1127-1132 (open access)

Boxwood Blight Maps

Boxwood Cleanliness Programs

Sanitizers & Sanitation Practices

Cultural Control

Ohkura, M., Nackley, L., Scagel, C., and Weiland, J. 2021. Call it “herbal distancing” Digger (published by the Oregon Association of Nurseries) August issue (open access)

Fungicide Options & Chemical Protection

Best Management Practices

Bush, E. Hansen, M. A., Dart, N., Hong, C. X., Bordas, A., and Likins, T. M. 2016. Best management practices for boxwood blight in the Virginia home landscape. Virginia Boxwood Blight Task Force (open access)

Bily, D., and Hong, C. X. 2023. Best management practices for boxwood blight in Virginia nurseries. Virginia Boxwood Blight Task Force (open access)

 

Boxwood Blight Biology

Spread of Blight Disease Illustration by Nina Shishkoff - Click Here

International Boxwood Seminars

Calamities of Georgia’s Boxwood Forests

By Dr. Iryna Matsiakh • December 21, 2022
by Dr. Iryna Matsiakh, Swedish University of Agricultural Sciences 

How do weather and climate impact boxwood blight? A modeling approach to aiding in boxwood disease management

By Dr. Len Coop • September 15, 2022
Presented by Len Coop - Associate Professor @Oregon Integrated Pest Management Center, Oregon State University, Corvallis, Oregon (USA) Boxwood blight is a fungal disease that can decimate boxwood plantings in most all settings and environments. The degree of injury can vary widely, depending on cultivar susceptibility, local disease severity, and weather, from nearly symptom-free to total destruction and death of boxwood plants. Dr. Len Coop will present how weather and climate affect both where the disease is of most concern, and when conditions may be most favorable for disease build-up. A demonstration of online tools will be given so that boxwood managers can apply these principles towards reducing and controlling this disease. Now boxwood blight model predictions can be delivered according to a subscriber's settings in their email in-box, making management decisions easier and less time consuming.

Biology & Management of Volutella Blight caused by Pseudonectria buxi

By Dr. Thomas Hsiang • August 17, 2022
Volutella blight is commonly found on boxwood plants worldwide. Although some consider it mainly a saprophyte surviving on dead tissues, it is capable of initiating disease on live wounded tissues. Here we present some background on the disease, some basic biology on how it causes infections, and end with its disease cycle and recommendations for management in nurseries.

Progress in Boxwood Blight Management in the United Kingdom & New Zealand: 1990s to 2021

By Dr. Matthew Cromey • March 17, 2022
In this seminar, Matthew will trace the progress of box blight and its management in the UK since it was first found in the mid-1990s. Early advice to gardeners was to remove all Buxus from gardens where the disease had been recorded. Since then, considerable progress has been made in keeping gardens free from box blight, but also to avoid the eradication of the host from gardens where it does appear. While it is still a difficult disease, there are increasing options for its management. The situation in the UK will be compared with that in New Zealand, where box blight has also been present since the 1990s.

Invasion, impact and management of box tree moth in Europe

By Dr. Marc Kenis • December 7, 2021
The box tree moth, Cydalima perspectalis, is a pest of boxwood (Buxus spp.) originating from East Asia. Since 2007, it has invaded Europe and the Caucasus, causing severe damage to planted and wild Buxus species, in particular the European boxwood Buxus sempervirens. In 2018, it was found in Toronto. In Europe, boxwood is quickly disappearing from private gardens, parks and forests, causing serious concern for the ecological survival of the tree species. In this presentation, the speaker will share the European perspective on the insect - its impact, identification, biology and management.

Boxwood Breeding & Selection for Blight Resistance

By Dr. Katrijn Van Laere • September 14, 2021
Boxwood (Buxus L. spp., Buxaceae) are popular woody landscape shrubs grown for their diverse forms and broad-leaved evergreen foliage, with an estimated $141 million economic impact in the U.S. alone. Boxwood plants grown in temperate zones worldwide are threatened by a blight disease caused by the ascomycete fungi Calonectria pseudonaviculata and C. henricotiae. While the disease can be mitigated somewhat through cultural practices and fungicides, the most sustainable long-term solution is the development of disease-resistant boxwood cultivars. This session delves into interspecific breeding and selection of boxwood towards resistance to Calonectria pseudonaviculata. Learn from Belgian researcher Katrijn Van Laere, who will share the creation of new boxwood cultivars resistant to boxwood blight, based on interspecific hybridisation and an efficient selection bio-assay.

Knowing & Growing Boxwood

By Lynn R Batdorf • June 4, 2021
by Lynn R Batdorf, International Cultivar Registration Authority 

Boxwood Blight - A 15 Year Love and Hate Relationship

By Dr. Thomas Brand • March 18, 2021
by Dr. Thomas Brand of Landwirtschaftskammer Niedersachsen, Germany

BBIG Boxwood Seminars

A logo for the horticultural research institute and thrive web series.

Tiny but Mighty: Unlocking the Microbiome Potential to Enhance Boxwood Resistance to Diseases and Environmental Stress

By Dr. Xiaoping Li • July 25, 2024

Boxwood Blight Insight Group (BBIG): Sanitation and Nursery Practices

By Dr. Fulya Baysal-Gurel • May 30, 2024
This educational session aims to equip nursery producers, gardeners, and plant health professionals with vital knowledge and strategies to combat the pervasive threat of Calonectria pseudonaviculata, the fungus responsible for the devastating boxwood blight. Boxwood blight, a serious concern for the horticulture industry, jeopardizes the health and viability of boxwood plants, significantly impacting the ornamental plant market. Addressing this issue, the webinar will delve into the critical control points in nursery production, emphasizing effective sanitation practices to prevent and manage the spread of this disease. Attendees of the webinar can expect to gain: An understanding of the lifecycle and spread of Calonectria pseudonaviculata. Insight into the latest research and developments in boxwood blight control. Practical guidance on implementing effective sanitation and preventive measures in nursery production. Strategies for identifying critical control points to mitigate the risk of boxwood blight in their operations. This webinar is essential for anyone involved in the cultivation, care, or management of boxwood 

In the Lab and the Landscape at the National Arboretum: Boxwood Genomics and AI Solutions for Blight Detection and Protection

By Dr. Fred Gouker • January 31, 2024
The Boxwood Blight Insight Group (BBIG) invites horticulturists, researchers, and plant enthusiasts to join an insightful webinar titled, "In the Lab and the Landscape at the National Arboretum: Boxwood Genomics and AI Solutions for Blight Detection and Protection." This webinar will offer an exploration of the latest boxwood research from the National Arboretum, with a focus on the intersection of boxwood breeding, genomics, and machine learning. Webinar Highlights: Cutting-edge Genomics Research: Learn about the latest developments in boxwood genomics and breeding strategies aimed at identifying genetic resistance to boxwood blight. Gain insights into current methodologies and breakthroughs at the National Arboretum. AI Solutions for Blight Detection: Discover how artificial intelligence (AI) is enhancing the detection and protection of boxwood in both laboratory settings and natural landscapes. The seminar will showcase innovative AI methods for recognizing and combatting boxwood blight, presenting a glimpse into the future of plant disease management. Engaging Presentation: Attendees will have the opportunity to ask questions fostering a collaborative environment for learning and idea exchange.

Battling Boxwood Blight

By Dr. James LaMondia • August 23, 2023
The Boxwood Blight Insight Group is pleased to host the next webinar in their on-going efforts to assist the industry manage boxwood health in the nursery and in landscapes.

BBIG On-Demand at Cultivate

2021

Boxwood Breeding at the U.S. National Arboretum

By Fred Gouker • July 18, 2021
Learn more about the development of improved woody ornamental landscape plants with superior ornamental value and that are tolerant to abiotic and biotic stress. Using the boxwood germplasm collection amassed at the U.S. National Arboretum, researchers are screening boxwood accessions for disease resistance, developing screening assays, and studying crossing and seed parameters to create new hybrids as part of a long-term breeding program to develop blight resistant boxwood cultivars. Presented by Fred Gouker, Research Geneticist, USDA-ARS, U.S. National Arboretum

Forecasting Systems for Boxwood Blight

By Len Coop & Brittany Barker • July 18, 2021
All too frequently we rely on best guesses—learn how you can take the guesswork out of the boxwood blight decision making process. Join this session for a look at what data you can input into a new forecasting system app that will help your team battle the blight! Presented by Len Coop, Associate Professor, Oregon State University

Fungicides and Management Implications for Boxwood Health

By Jim LaMondia • July 18, 2021
Understanding the latest research in fungicides in the battle for boxwood health is a key component in managing your boxwood population, whether in a nursery or in a landscape. Join us for insights into fungicides, spore dispersal, and management implications. Presented by Jim LaMondia, Chief Scientist, Connecticut Agricultural Experiment Station 

Boxwood Blight Research: What's the BBIG Deal?

By Chuan Hong • July 18, 2021
The Boxwood Blight Insight Group (BBIG) is a team of scientists working together on an USDA National Institute of Food and Agriculture – Specialty Crop Research Initiative (SCRI) project, in partnership with stakeholders and international collaborators. Learn how this transdisciplinary team aims to safeguard boxwood—the nation’s #1 evergreen ornamental shrub crop—from blight disease.

2022

Observations about boxwood blight in the nursery industry

By Jerry Weiland • July 17, 2022

Tools for training English and Spanish-speaking workers to scout for boxwood blight

By Luisa Santamaria • July 17, 2022

Pesticide coverage of boxwood plants with nursery sprayers

By Jay Pscheidt • July 17, 2022

Effect of sanitizers on Calonectria pseudonaviculata, causal agent of boxwood blight

By Fulya Baysal-Gurel • July 17, 2022
Presented by Fulya Baysal-Furel, Tennessee State University 

Outreach to Different Stakeholders

Horticulturists

Managing boxwood blight and box tree moth

By Dr. Chuan Hong of Virginia Tech and Dr. Greg Simmons of USDA Animal and Plant Inspection Service
This talk was presented on the EPA IPM Webinar series on March 5, 2024

By Dr. Lynn Batdorf, International Registration Authority – Buxus

This talk was presented at the third BBIG Annual Meeting on May 9, 2024 

By Lynn Batdorf, Chris Cooper, Fulya-Basal-Gurel, Leslie Hollandsworth, Katy Kilbourne, Booker T. Leigh, Bennett Saunders at a day-long workshop in the Dixon Gallery and Gardens, Memphis, TN, February 18, 2022 

Help Is On The Way

Gress, A. 2024. Help is on the way – don’t give up on box just yet. Floraculture International (March 2024 issue):18-19.

Landscaping Professionals

By Mr. Michael Gaines • December 1, 2023

This talk was presented at a quarterly BBIG Project Advisory Panel meeting on December 1, 2023, sharing his experience and tips on how to successfully manage boxwood blight in the landscapes.

First Responders

January 17, 2024

First Session

  • Introduction: boxwood blight effects and how we are coping by Margery Daughtrey
  • Boxwood blight pathogen morphology and how it differs from other pathogens by Xiao Yang
  • Diagnostic assays for the boxwood blight pathogens Calonectria pseudonaviculata and C. henricotiae by Doug Luster
  • Sampling and detection methods for boxwood blight in nurseries by Mana Ohkura

Second Session

  • Boxwood, the plant and its blight symptom expression by Nina Shishkoff
  • New IPM tools for boxwood blight by Chuan Hong

By Ms. Margery Daughtrey, Dr. Russ Bullock, and Abigail Weisner · April 11 to 13, 2022

Science Communities

Idea Café – Boxwood Blight Insight Group (BBIG) Fighting a Good Fight against Boxwood Blight

At the Annual Meeting of the American Phytopathological Society · August 2, 2021

Symposium – Ornamental Production Challenges and Perspectives: A Case Study of Boxwood Blight

At the 99th Annual Meeting of the American Phytopathological Society – Southern Division in Chattanooga, TN, March 7 to 10, 2022

Symposium – Epidemiology, Diagnosis, and Management of an Emerging Disease – Boxwood Blight

At the Annual Meeting of the American Phytopathological Society in Pittsburgh, PA, August 6 to 10, 2022

International Boxwood Blight Epidemiology (IBBE) Working Group Meetings

1st IBBE Meeting (August 10, 2021) with three invited presentations

View Recording

Boxwood blight epidemiology: research goals, approaches, key processes and considerations, collaboration and communication plans

Chuan Hong of Virginia Tech

Boxwood epidemiology research updates

By Drs. Srikanth Kodati and Jim LaMondia of Connecticut Agricultural Experiment Station

Boxwood blight infection risk forecasting models

By Drs. Len Coop and Brittany Barker of Oregon State University

2nd IBBE Meeting (October 25, 2021) with two invited presentations

View Recording

Predicting boxwood blight infection and establishment risk using CLIMEX, correlative, and DDRP modeling platforms

By Drs. Len Coop and Brittany Barker of Oregon State University

Long-term monitoring of Boxwood blight symptom development in an open-air nursery in coastal California – update

by Drs. Wolfgang Schweigkofler and Nilwala Abeysekara of Dominican University of California

3rd IBBE Meeting (February 7, 2022) with one invited presentation

View Recording

What weather conditions make an area hotspot for boxwood blight 

by Dr. Urmila Adhikari of Virginia Tech

4th IBBE Meeting (May 9, 2022) with one invited presentation

View Recording

Attempting to understand boxwood blight epidemiology in landscape plantings through diagnostic sample confirmations

by Dr. Andrew Loyd of Bartlett Tree Experts

5th IBBE Meeting (October 17, 2022) with one invited presentation

View Recording

Models for boxwood blight infection and establishment risk

by Drs. Len Coop and Brittany Barker of Oregon State University

More Resources

Boxwood

International Checklist List of Cultivated Buxus L.- Click Here

Batdorf, L. R., and Daughtrey, M. L. 2021. Boxwood blight nomenclature - Click Here

Volutella Blight & Other Boxwood Diseases

Boxwood Browning, Blights, and Cankers – 2023 Updates by Todd Abrahamson of Purdue University on July 25, 2023 in Landscape Report Issue: 23-11

Re-Visiting Volutella and Browned Boxwood by Joe Boggs of Ohio State University on July 17, 2023 in Buckeye Yard & Garden onLine

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