Boxwood Blight Insight Group Knowledge Center - BBIG

Herbal Distancing: Keeping Boxwood in Your Nursery Free from Blight

Fri, 30 Jan 2026 18:40:20 GMT

Learn how your nursery production practices can impact boxwood blight risk and your potential for outbreaks. Whether you’re currently dealing with this disease or working to prevent it, understanding key risk factors is essential for protecting your entire boxwood inventory. Join plant disease expert Jerry Weiland as he examines real-world case studies demonstrating how boxwood blight enters nurseries and spreads via common production activities. This webinar will cover critical factors that influence disease development and spread, including plant size and spacing, cultivar selection, environmental conditions (temperature and moisture), and fungicides. You’ll leave with practical management recommendations and actionable strategies for preventing and controlling boxwood blight in your operation.

Prospecting for Biocontrols

Fri, 14 Mar 2025 15:42:28 GMT

It is neither economically sustainable nor environmentally acceptable to make multiple fungicide applications to protect boxwood, a key nursery crop and iconic landscape plant, from boxwood blight.

This webinar highlights some of the successes at Virginia Tech in the search for potent biological agents for blight control. Dr. Kong will describe the biocontrol development process: how and where candidate microorganisms were discovered, and how their antagonistic activities against the boxwood blight pathogen Calonectria pseudonaviculata were measured in the laboratory—followed by evaluation on whole plants in controlled environments and then in field trials in western North Carolina. Some biocontrol agents have not only shown blight control at similar levels to the fungicide standard but have also substantially promoted boxwood growth.

Dr. Kong will also share the ongoing research with Burkholderia SSG, the top-performer in her lab’s trials. These studies provide an example of the exploration of the microbial world as a source of powerful tools to promote plant health and production.

Cleaning up Boxwood Blight with a Full Spectrum of Sanitizers

Thu, 06 Feb 2025 17:30:52 GMT

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

Thu, 25 Jul 2024 19:13:47 GMT

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

Thu, 30 May 2024 14:56:30 GMT

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

Wed, 31 Jan 2024 16:15:45 GMT

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

Wed, 23 Aug 2023 20:07:34 GMT

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.

In this webinar, Dr. Jim LaMondia will present research results and recent discoveries relating to boxwood blight management in nursery and landscape settings. These tactics will include targeted fungicide use, host plant genetics and cultural controls.

A Combined Approach for Early In-Field Detection of Beech Leaf Disease Using Near-Infrared Spectroscopy and Machine Learning

Sun, 23 Jul 2023 14:50:07 GMT

by Dr. Carrie Fearer of University of New Hampshire

Basics of Box Tree Moth

Tue, 11 Apr 2023 14:37:41 GMT

Box tree moth observations in Europe by Mr. Bennett Saunders of Saunders Genetics LLC

Phenology of the box tree moth in Western New York by Dr. Alejandro Del-Pozo of Virginia Tech

Managing BTM in the nursery by Dr. Jeanine West, Grower Technical Analyst, Landscape Ontario

Calamities of Georgia’s Boxwood Forests

Wed, 21 Dec 2022 14:36:08 GMT

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

Thu, 15 Sep 2022 13:34:36 GMT

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

Wed, 17 Aug 2022 13:32:19 GMT

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.

Observations about boxwood blight in the nursery industry

Sun, 17 Jul 2022 13:54:50 GMT

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

Sun, 17 Jul 2022 13:53:37 GMT

Pesticide coverage of boxwood plants with nursery sprayers

Sun, 17 Jul 2022 13:51:48 GMT

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

Sun, 17 Jul 2022 13:50:06 GMT

Presented by Fulya Baysal-Furel, Tennessee State University

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

Thu, 17 Mar 2022 13:29:59 GMT

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.

Research Publication 2021

Fri, 31 Dec 2021 20:47:55 GMT

Avenot, H. F., Baudoin, A., and Hong, C. X. 2021. Conidial production and viability of Calonectria pseudonaviculata on infected boxwood leaves as affected by temperature, wetness and dryness periods. Plant Pathology published online at
Click to Read the Article

Publication requires subscription to be viewed

J. A. LaMondia, E. Allan-Perkins, S. Kodati; Factors affecting boxwood blight spread under landscape conditions . Journal of Environmental Horticulture, September 2021; 39 (3): 100–107. doi:
Click to Read the Articl e

Kong, P.; Sharifi, M.; Bordas, A.; Hong, C. Differential Tolerance to Calonectria pseudonaviculata of English Boxwood Plants Associated with the Complexity of Culturable Fungal and Bacterial Endophyte Communities.
Click to Read the Articl e

Bika R, Copes W, and Baysal-Gurel F. 2021. Comparative performance of sanitizers in managing plant-to-plant transfer and postharvest infection of Calonectria pseudonaviculata and Pseudonectria foliicola on boxwood. Plant Disease. https://doi.org/10.1094/ PDIS-03-21-0481-RE

Castroagudín VL, Shishkoff N, Stanley O, Whitesell R, Olson T, and Crouch JA. 2021. First report: Co-infection of Sarcococca hookeriana (sweetbox) by Coccinonectria pachysandricola and Calonectria pseudonaviculata causes a foliar disease of sweetbox in Pennsylvania. Plant Disease https://doi.org/10.1094/PDIS-1006-1020-1198-PDN

LeBlanc N, Cubeta MA, and Crouch JA. 2021. Population genomics trace clonal diversification and intercontinental migration of an emerging fungal pathogen of boxwood. Phytopathology 111:184-193. https://doi.org/10.1094/phyto-06-20-0219-fi

Shishkoff N, Miller ME, and Cubeta MA. 2021. Rooting response of boxwood cultivars to hot water treatment and thermal sensitivity of Calonectria henricotiae and C. pseudonaviculata in diseased boxwood (Buxus spp.). Journal of Environmental Horticulture 39:1-10. https://doi.org/10.24266/0738-2898-39.1.1

Yang X, McMahon MB, Ramachandran SR, Garrett WM, LeBlanc N, Crouch JA, Shishkoff N, and Luster DG. 2021. Comparative analysis of extracellular proteomes reveals putative effectors of the boxwood blight pathogens, Calonectria henricotiae and C. pseudonaviculata. Bioscience Reports 41(3):BSR20203544. https://doi.org/10.1042/BSR20203544

Invasion, impact and management of box tree moth in Europe

Tue, 07 Dec 2021 14:27:54 GMT

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.

Analyzing the Structural Shifts in U.S. Boxwood Production Due to Boxwood Blight

Tue, 28 Sep 2021 19:39:32 GMT

Journal of Environmental Horticulture (2021) 39 (3): 91–99.

The purpose of this study is to examine the changes in the sales of boxwood (Buxus spp.) that have occurred in boxwood production states. We theorize that some of the shifts in production areas over the period from 2009 to 2019 have been impacted by the introduction of boxwood blight into the United States. Boxwood blight (Calonectria pseudonaviculata) was first observed in the U.S. in 2011 by plant pathologists in 8 states: Connecticut, Maryland, Massachusetts, New York, North Carolina, Oregon, Rhode Island, and Virginia. The disease has now been seen in 30 states plus the District of Columbia. The data used for this analysis is from the Census of Horticultural Specialties (CHS), a survey administered by the United States Department of Agriculture, National Agricultural Statistics Service (USDA-NASS) every five years. The findings from this analysis of the Census of Horticultural Specialties data from 2009 to 2019 indicate that there were already shifts occurring in boxwood markets prior to the introduction of boxwood blight. However, boxwood blight has exacerbated the supply chain challenges for green industry participants by limiting production in certain areas of the country, increasing the costs of producing boxwood compared to other evergreen shrubs, and perhaps dampening the demand from what might have been without the existence of the blight.

Click on the link to read the full articles - https://doi.org/10.24266/0738-2898-39.3.91

Factors Affecting Boxwood Blight Spread Under Landscape Conditions

Tue, 28 Sep 2021 19:37:13 GMT

Journal of Environmental Horticulture (2021) 39 (3): 100–107.

We investigated the spread of boxwood blight in a simulated landscape under conducive natural conditions from 2017 to 2019. We used strict sanitation to greatly reduce or eliminate spread by contact. Movement of the pathogen from an infected source plant was limited to one plant, likely spread by means of water splash. Plants were mulched with composted hardwood chips and mulching likely was primarily responsible for limiting spread to only the adjacent plant. Boxwood (Buxus spp.) cultivar susceptibility and fungicide spray programs influenced the incidence of spread and severity of disease; in 2018 and 2019 the more susceptible cultivar had higher disease incidence and severity, respectively, than less susceptible cultivars. Fungicide application only caused a small reduction in disease incidence in 2018. We also demonstrated that spores in clumps could survive extended dry conditions, indicating the importance of sanitation procedures on reducing spread. This experiment demonstrates that boxwood blight can be controlled in a landscape by following best management practices including cultural, sanitation, host susceptibility and fungicide application tactics.

Click the link to read the full article - https://doi.org/10.24266/0738-2898-39.3.100

Boxwood Breeding & Selection for Blight Resistance

Tue, 14 Sep 2021 13:25:42 GMT

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.

Call It 'Herbal Distancing'

Fri, 27 Aug 2021 19:29:51 GMT

How container spacing can help reduce the impact of boxwood blight in nursery production.

It’s been a year and a half since the COVID-19 pandemic started. We have been hearing how social distancing prevents the spread of the virus and we see signs everywhere indicating we should stay at least 6 feet apart.

It turns out, social distancing may work to keep boxwood blight from spreading in your nursery too.

Wait a minute — boxwood plants can’t move, and they don’t reach out for hugs!

Well, they are often grown tightly packed together with branches overlapping each other, so let’s say they’re as close as holding hands.

In this study, we share results from a recent experiment where we grew boxwood plants either packed tightly together or spaced further apart under different irrigation frequencies to see how that impacted the spread of boxwood blight from infected plants to healthy plants.

Continue reading the article: http://www.diggermagazine.com/call-it-herbal-distancing/

Courtesy of the Oregon Association of Nurseries’ Digger Magazine.

By Mana Ohkura, Lloyd Nackley, Carolyn Scagel and Jerry E. Weiland

Dr. Lloyd Nackley is an assistant professor of horticulture and Extension agent at Oregon State University, specializing in nursery crop production. He can be reached at lloyd.nackley@oregonstate.edu .

Dr. Carolyn Scagel is a plant physiologist with the Horticultural Crops Research Laboratory, USDA Agricultural Research Service in Corvallis, Oregon. She can be reached at Carolyn.Scagel@usda.gov .

Dr. Jerry E. Weiland is a research plant pathologist with the Horticultural Crops Research Laboratory, USDA Agricultural Research Service in Corvallis, Oregon. He can be reached at Jerry.Weiland@usda.gov .

Dr. Mana Ohkura is a postdoctoral scholar in Botany and Plant Pathology at Oregon State University in Corvallis, OR. She can be reached at ohkuram@oregonstate.edu .

Acknowledgments
The authors would like to thank Jesse Mitchell, Dalyn McCauley, and Bryan Beck for their assistance with this study.

Boxwood Breeding at the U.S. National Arboretum

Sun, 18 Jul 2021 14:05:22 GMT

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

Sun, 18 Jul 2021 14:04:05 GMT

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

Sun, 18 Jul 2021 14:02:52 GMT

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?

Sun, 18 Jul 2021 14:01:13 GMT

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.

Presented by Chuan Hong, Professor, Virginia Tech

Knowing & Growing Boxwood

Fri, 04 Jun 2021 13:19:36 GMT

by Lynn R Batdorf, International Cultivar Registration Authority

Boxwood Blight - A 15 Year Love and Hate Relationship

Thu, 18 Mar 2021 13:13:13 GMT

by Dr. Thomas Brand of Landwirtschaftskammer Niedersachsen, Germany

The Plant Microbiome & How to Study It With High Throughput Sequencing

Tue, 16 Feb 2021 15:48:55 GMT

by Dr. Xiaoping Li of Virginia Tech

BBIG Grant Award for Boxwood Research with an HRI Connection

Fri, 05 Feb 2021 17:09:27 GMT

New Website & Webinar Series Announced

WASHINGTON, DC and COLUMBUS, OH — USDA NIFA awarded a confederation of researchers a multiyear grant to help elucidate the mysteries of boxwood blight and its management.

The Boxwood Blight Insight Group, or BBIG, has several key areas of focus over the next four years, including the following.

Conduct impact analysis to generate data that better resonate with state and federal policy makers, such as disease loss estimates and model economic analysis of best management practices.
Identify critical control points in nursery production to help pinpoint best sampling points and develop site-specific best management practices.
Assist landscape managers to better manage the disease by looking at potential biological control agents, agents that activate boxwood plant defenses, fungicide optimization, and mulch optimization.
Build boxwood resilience through identifying resistant cultivars, understanding the soil microbiome, and breeding efforts utilizing modern technologies.
Create a better understanding of boxwood blight infections (symptom and disease development and expression) in the Pacific Northwest through expanded nursery surveys.
Develop an extensive outreach network including materials such as a pictorial guide of symptoms under certain environmental conditions, videos to help scouting efforts, and materials to help train industry, research, and extension personnel.

Industry has much to gain from the research. Bennett Saunders, General Manager of Saunders Genetics and former President of the American Boxwood Society, commented, “When boxwood blight hit the United States, we were deeply concerned that this might be the end for Boxwood. In Europe, there was very little research and there were very few answers. However, the research community in the United States was up to the challenge. They embraced the dire situation and began giving us answers very quickly.”

“This most recent grant will continue to give boxwood growers practical, understandable, and effective tools to combat boxwood blight. We look forward to seeing their work and their results!”

HRI has joined BBIG in their efforts as a collaborator on the outreach team. HRI’s role includes hosting the materials generated on its website, distributing newsletters, and working closely with the researchers on presentation of information. The new website is accessible through www.hriresearch.org and www.boxwoodhealth.org .

Ken McVicker, President of HRI, welcomed the opportunity by saying, “Boxwood blight continues to threaten nursery production and landscapes, and much needs to be learned and understood. We at HRI are excited for this announcement both for the discovery of critical information that will help us manage this disease and also for the opportunity to grow HRI’s outreach program. Working with BBIG is a wonderful opportunity for HRI to improve our efforts to connect research to industry.”

That connection begins with a series of boxwood research webinars launching on March 18, 2021 with Boxwood Blight: A 15-Year Love-Hate Relationship, with speaker Dr. Thomas Brand, Chamber of Agriculture of Lower Saxony. This session will summarize the 15 years of research and share the successes and difficulties of blight control in gardens and parks in Germany, where the fight for boxwood has been ongoing since 2004. Attendance is free and more details are available at: http://bit.ly/3rrnWxu .

T he Horticultural Research Institute (HRI) proudly supported the funding of BBIG. Back in 2013, HRI established a special research initiative dedicated to boxwood blight research shortly following its identification in the US. HRI reopened the fund in 2018 to work with researchers towards a standardized protocol where boxwood varieties can be assessed for boxwood blight resistance. This research continues through the USDA ARS’s Floriculture and Nursery Research Initiative (FNRI), also supported by HRI. The BBIG project will take boxwood blight research to the next level and will benefit both production and landscape management of boxwoods.

Microsoft Teams Training

Mon, 20 Jul 2020 14:47:23 GMT

by Paige Ghra of Virginia Tech on July 20, 2020

Research Publication 2020

Tue, 16 Jun 2020 19:50:59 GMT

Baysal-Gurel F, Jennings C, and Simmons T. 2020. Evaluation of fungicides for the control of boxwood blight, 2020. Plant Disease Management Reports 15:OT002. https://www.plantmanagementnetwork.org/pub/trial/PDMR/volume15/

Castroagudín VL, Weiland JE, Baysal-Gurel F, Cubeta MA, Daughtrey ML, Gauthier NW, LaMondia J, Luster DG, Hand FP, Shishkoff N, Williams-Woodward J, Yang X, LeBlanc N, and Crouch JA. 2020. One clonal lineage of Calonectria pseudonaviculata is primarily responsible for the boxwood blight epidemic in the United States. Phytopathology 110:1845-1853. https://doi.org/10.1094/phyto-04-20-0130-r

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

Gouker FE, Guo YH, and Pooler MR. 2020. Using acetone for rapid PCR-amplifiable DNA extraction from recalcitrant woody plant taxa. Applications in Plant Sciences 8:e11403. https://doi.org/10.1002/aps3.11403

Hall CR, Hodges AW, Khachatryan H, and Palma MA. 2020. Economic contributions of the green industry in the United States in 2018. Journal of Environmental Horticulture 38:73-79. https://doi.org/10.24266/0738-2898-38.3.73

Hall CR, and Knuth MJ. 2020. An update of the literature supporting the well-being benefits of plants: Part 4 – available resources and usage of plant benefits information. Journal of Environmental Horticulture 38:68-72. https://doi.org/10.24266/0738-2898-38.2.68

LaMondia JA. 2020. Curative fungicide activity against Calonectria pseudonaviculata, the boxwood blight pathogen. Journal of Environmental Horticulture 38:44-49. https://doi.org/10.24266/0738-2898-38.2.44

LaMondia JA, and Maurer K. 2020. Calonectria pseudonaviculata conidia dispersal and implications for boxwood blight management. Plant Health Progress 21:232-237. https://doi.org/10.1094/PHP-04-20-0024-RS

Sacher GO, Weiland JE, Putnam ML, Crouch JA, and Castroagudin VL. 2020. Confirmation of Calonectria pseudonaviculata causing boxwood blight of Buxus cultivars in Oregon. Plant Disease 104:1862. https://doi.org/10.1094/pdis-01-20-0078-pdn