Boxwood Blight Task Force
The Virginia Boxwood Blight Task Force provides leadership in safeguarding and protecting the ornamental horticulture industry, historical gardens, and landscape plantings from boxwood blight.
The following BMPs are guidelines for boxwood growers to avoid introduction of the boxwood blight pathogen or, if the disease is already present, to manage the disease in the most effective manner and avoid spread of the disease to new locations. Each BMP is specialized for individual boxwood growing situations.
|Best Management Practice||Situation|
|Best Management Practices for Boxwood Blight for Virginia Landscapes, Public Grounds and Historic Gardens||professional landscapers, public grounds and historic garden situations|
|Best Management Practices for Boxwood Blight in the Virginia Home Landscape||residential boxwood growers|
|Best Management Practices for Boxwood Blight in Virginia Production Nurseries WITHOUT Boxwood Blight||commercial nursery production|
|Best Management Practices for Boxwood Blight in Virginia Production Nurseries WITH Boxwood Blight||commercial nursery production|
|Best Management Practices for Virginia Retail Nurseries WITHOUT Boxwood Blight||retail garden stores|
|Best Management Practices for Virginia Retail Nurseries WITH Boxwood Blight||retail garden stores|
|Best Management Practices for Boxwood Blight for Boxwood Greenery Producers||boxwood greenery producers (i.e. used for holiday greenery) and boxwood tippers|
Sanitizer recommendations for the boxwood blight pathogen
Note: Only ethanol products provide some control of microsclerotia and other pathogen structures (e.g. mycelium, spores, chlamydospores) in plant debris; thus, it is VERY important to wash off surface soil and/or debris before proceeding with any recommended sanitizing procedure.
|Active ingredient||Example of brand name||Concentration||Contact time/application|
|Ethanol in spray or liquid form||Lysol disinfectant aerosol spray (Brand III)||70% Ethanol or greater or Lysol Disinfectant Spray Brand III with 58% ethanol and 0.1% dimethyl benzyl ammonium saccharinate||For spray applications: Apply to surface and allow to air-dry. For liquid application dip tools for 5 min|
|Sodium hypochlorite (5.25% or 8.25)||Clorox and other household brands||Prepare 1:9 solution of 5.25% bleach or 1:14 solution of 8.25% bleach. Must be prepared fresh||10-15 min. for equipment surfaces; dip tools for 5 min|
|Hydrogen dioxide||Oxidate, Zerotol||5-10 min|
|Hydrogen peroxide, peroxyacetic acid, and octanic acid||Xeroton 3 (X3)||10 min|
|Phenolic compounds (O-benzyl-p-chlorophenol)||Lysol Brand Concentrate Disinfectant||Prepare solution of 1.25 – 2.5 oz/gal.||At least 5 min|
Data compiled from: (1) Douglas, S.M., 2013. Efficacy of sanitizing agents to refine best management practices for the boxwood blight pathogen Calonectria pseudonavicula. APS poster, Annual meeting , Aug. 10-14, Austin TX, (2) Shishkoff, N., 2014. Survival of microsclerotia of Calonectria pseudonaviculata (the boxwood blight pathogen) treated with a variety of sterilants. APS poster, Potomac Division Meeting, March 12–14, Annapolis, Maryland, (3) Dart, N. L., Hong, C. X., Allen, C., 2014. Efficacy of bleach and ethanol as sanitizers on conidia and infected leaf tissue colonized with mycelium and microsclerotia of the boxwood blight pathogen, Calonectria pseudonaviculata. Unpublished.
Version 1, published December 2014
|Table 1. Fungicides for boxwood blight management, home grower use.|
|Active ingredient||Trade name||Efficacy1||FRAC group2|
|Chlorothalonil||Broad Spectrum Landscape & Garden Fungicide (Ferti-lome); Vegetable, Flower, Fruit and Ornamental Fungicide (Hi-Yield); Fung-onil (Bonide); Ortho Max Garden Disease Control or Ortho Diseease B Gon (Scotts)||E||M5|
|Table 2. Fungicides for boxwood blight management, professional use|
|Active ingredient||Trade name||Effi-
|√||√||√||Propiconazole||Banner MAXX, Procon-Z||F-G||3|
|√||√||√||Propiconazole + chlorothalonil||Concert, Concert II||E||3+M5|
|√||√||Trifloxystrobin + triadimefon||Strike Plus 50 WDG||G-E||3+11|
|√||√||Myclobutanil||Eagle WSP, Rally 40WSP||F-G||3|
butanil 20EW T&O
|√||√||√||√||Thiophanate methyl||Cleary 3336 F, Fungo Flo||F||1|
|√||√||√||√||Mancozeb||Fore 80 WP Rainshield, Protect DF||G||M3|
|√||√||√||√||Chlorothalonil||Daconil Weather Stik Flowable Fungicide||E||M5|
|√||√||√||√||Chlorothalonil + thiophanate methyl||Spectro 90WDG||E||1+M5|
|√||√||√||√||Boscalid + pyraclostrobin||Pageant||G||7+11|
|√||√||√||Cyprodinil + fludioxonil||Palladium||F-E||9+12|
1F=Fair, G=Good, E=Excellent
- Effectiveness ratings are based on limited research. Results can vary depending on environmental conditions, formulation of a pesticide, and application method and timing. These ratings are intended as general guides only.
- Sources of efficacy information: Gehesquière B. (2014). Phd Thesis. Ghent University, Belgium; Ivors, et al. 2013. Plant Dis. Manag. Rep. 7:OT014. doi: 10.1094/PDMR07; LaMondia, J.A. 2015. Plant Dis. 99: in press; Henricot B. and Wedgwood E. 2013. Plant Health Progress. doi:10.1094/PHP-2013-1024-01-RS; and unpublished research.
2FRAC Group: classification based on fungicide mode of action (www.frac.info). Rotate any fungicide at risk of resistance development with products that have a different mode of action (i.e., in a different FRAC group).
It is the user’s responsibility to read and follow product label directions for all products. Commercial products are named in this publication for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products which also may be suitable.
- Boxwood Blight Cleanliness Program, Virginia Department of Agriculture and Consumer Services
- Boxwood Blight: A New Disease of Boxwood Found in the Eastern U.S., Virginia Cooperative Extension factsheet
- Boxwood Blight Management, Department of Plant Pathology, North Carolina State University
- Local Virginia Cooperative Extension Offices
- Plant Disease Clinic Disease Alerts
|Anton Baudoin||Associate Professor of Plant Pathology||Department of Plant Pathology, Physiology and Weed Science, Virginia Tech|
|Adria Bordas||Extension Agent||Virginia Cooperative Extension, Fairfax County|
|Elizabeth Bush||Extension Plant Pathologist||Department of Plant Pathology, Physiology and Weed Science, Virginia Tech|
|Norm Dart||State Plant Pathologist||Office of Plant Industry Services, Virginia Department of Agriculture and Consumer Services|
|Mary Ann Hansen||Extension Plant Pathologist||Department of Plant Pathology, Physiology and Weed Science, Virginia Tech|
||Professor and Extension Specialist of Plant Pathology||Hampton Roads Agricultural Research and Extension Center, Virginia Tech|
|Ping Kong||Research Scientist||Hampton Roads Agricultural Research and Extension Center, Virginia Tech|
|T. Mike Likins||County Agent||Chesterfield County Extension|
|Tina MacIntyre||State Cooperative Agricultural Pest Survey Coordinator||Office of Plant Industry Services, Virginia Department of Agriculture and Consumer Service|
|David Gianino||State Plant Regulatory Official||VDACS|