News & Resources


“Plants Bees Like Best” Publication
Click here to view the “Plants Bees Like Best” brochure detailing Bee-Friendly Trees & Shrubs

Best Management Practices (BMPs) for Bee Health in the Horticultural Industry
Click here to view the BMPs released January 2017, Version 1.0

Funded Research
The Horticultural Research Institute is pleased to provide funding for independent research projects related to pollinator health. Click here to learn about the projects.

Research Results



Horticultural Research Institute Releases Best Management Practices (BMPs) for Bee Health in the Horticultural Industry

WASHINGTON, DC and COLUMBUS, OH—January 19, 2017—The Horticultural Research Institute, the research foundation of AmericanHort, is pleased to announce the release of Best Management Practices (BMPs) for Bee Health in the Horticultural Industry.

BMPs are intended to inform horticultural professionals about the green industry’s impact on bee health. Through the use of BMP guidelines, horticulture can continue to play an important role in pollinator health.

In 2015, the Horticultural Research Institute recognized the need for sound research to develop best production and management practices, educate, and empower the green industry. HRI, in collaboration with AmericanHort, continues to directly fund and leverage research to refine science-based guidance on horticultural practices and protecting bee and pollinator health. As part of the broad-based Horticulture Industry Bee & Pollinator Stewardship Initiative that includes industry and consumer outreach and the establishment of industry best practices, HRI has directly funded four important research projects, launched the Grow Wise, Bee Smart website, and joined the Million Pollinator Garden Challenge campaign.

Jon Reelhorn, HRI President, states, “Investment in research surrounding horticulture’s role in pollinator health is part of HRI’s longstanding commitment to fostering new information relevant to horticultural practices, techniques, and principles. We are pleased to have developed a set of BMPs that offer specific guidance to the industry to refine their stewardship role in bee health.

Pollinators as a whole encompass a diverse population of thousands of different species, such as managed honey bees, wild bees, butterflies, birds, and bats. Protection of pollinators in general, especially bees, continues to be a major concern among the general public and within the green industry. Several culprits have been identified as factors contributing to managed honey bee losses, including Varroa mites, other pests/diseases of bees, loss of habitat and nutrition, and off-target effects of pesticides. Alternatively, wild, unmanaged bee populations are most greatly affected by landscape changes and habitat degradation.

HRI developed the BMPs, which cover greenhouse and nursery production, woody ornamentals, and managed landscapes, with the assistance of researchers and apiarists throughout North America. Updates to these recommendations will be made as additional research results regarding bee and pollinator health are released.

For the full Best Management Practices (BMPs) for Bee Health in the Horticultural Industry, visit the GrowWise, Bee Smart website. To learn more about the Horticultural Research Institute and its efforts in developing science-based recommendations for the industry, visit the HRI website or contact Jennifer Gray, HRI Administrator by email or (614) 884-1155.


New Light Shed on Bee Parasites, Pathogens
April 28, 2016; Jill Calabro, PhD, Horticultural Research Institute

With all the discussion about honey bee health, the implication is that a wealth of information exists about what is normal or healthy for a honey bee. Sadly, there is not. Very little information exists detailing the presence of honey bee pests in the US. Finally we are getting some answers.

The National Honey Bee Disease Survey was initiated in 2009 to document honey bee pests and pathogens throughout the US in the response to concerns over declining honey bee populations and to meet import/export requirements for international trade. A report summarizing the first five years of sample collection has just been published. Researchers detailed their observations on mites, fungal pathogens, and viruses. A critical component of the survey is to also analyze pesticide residues in apiaries; however, this information was not included in this report.

During the first five years of the survey, populations of Varroa mite and Nosema spp. (a fungal pathogen of honey bees) were far greater than expected. From 2009-2014, Varroa mites were positively identified in 87 – 98% of the sampled apiaries, and their populations were surprisingly seasonal. The highest monthly Varroa mite loads were observed in August through November. Furthermore, 55-70% of all sampled apiaries had mite populations over the critical economic threshold level at the critical time right before winter. Nosema spp. incidence ranged from 42-79% of sampled apiaries during 2009-2014, and was greater in migratory colonies (than stationary colonies).

Varroa mites are closely linked to virus infections; so, it follows that researchers saw a high incidence of viral infections associated with high mite populations. Eight viruses were monitored each year. Dwarf wing virus consistently had the greatest incidence with detected levels above 80% each year, while chronic bee paralysis virus doubled annually since 2010.

There is some good news:  three exotic pest problems of, Tropilaelaps mite, slow paralysis virus, and Apis cerana (Asian honey bee), have not yet been detected in the US.

Researchers at the University of Maryland and USDA lead this multiyear effort. This first summary will serve as a baseline to measure trends and patterns over time, bringing much needed information to identify drivers of poor bee health.  Plus it will be useful for detection of changes and new pests. Researchers also plan to correlate colony health to in-hive pesticide residues.

Pollinator Garden Point-of-Purchase Materials Released: Communicator Toolkit Provides Additional Industry Resources
WASHINGTON and COLUMBUS, OH – March 2, 2016 –
The Horticultural Research Institute, the research affiliate of AmericanHort, is pleased to announce the creation of new point-of-purchase materials designed for garden retail display. The signage promotes the Million Pollinator Garden Challenge…

WEBINAR! Bee Savvy: Pollinator Opportunities Ahead
Watch the recorded Bee Savvy webinar online. It covers:

  1. the goals of the Grow Wise. Bee Smart™ pollinator stewardship initiative launched by AmericanHort and the Horticultural Research Institute
  2. the Million Pollinator Garden Challenge
  3. Tammy Behm and Jennifer Schamber of Greenscape Gardens, St. Louis, MO, describing their community-based approach to embracing the pollinator issue that has led to related sales doubling this year over last. They offered tricks, tips, and lessons learned. This is sweet knowledge you’ve just got to hive…I mean, have.


Download our FAQ and brochure. They are helpful tools for your staff teams and customers in understanding horticulture’s critical role in pollinator health.

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What Horticulture Needs to Know About Pollinator Health Video