Posted on August 14, 2013 · Posted in Bees

In 2013, Friends of the Earth U.S. and the Pesticide Research Institute released Gardeners Beware: Bee- Toxic Pesticides Found in “Bee-Friendly” Garden Plants Sold Nationwide, a first-of-its-kind pilot study on the prevalence of highly bee-toxic neonicotinoid pesticides in bee-attractive plants commonly purchased by home gardeners in three U.S. cities. In 2014, we published a new report Gardeners Beware 2014 that expanded the scope of the pilot study to include 18 locations in the U.S. and Canada and analyzed neonicotinoid concentrations in flowers separately from stems and leaves. The results of these studies demonstrated that many of the seedlings and plants sold in nurseries and garden stores across the U.S. were being treated with neonicotinoids and sold to consumers with no warning that the plants could be toxic to bees and other pollinators.

After the release of these reports, Friends of the Earth and allies in the U.S. and Canada called on Home Depot, Lowe’s and other garden retailers to stop selling plants pre-treated with neonicotinoid pesticides and off-the-shelf neonicotinoid products; to make third-party certified organic starts and plants available; and to educate customers about their policies to protect bees and other pollinators. More than one million people signed petitions, and thousands of activists made calls, delivered letters and visited stores in person requesting these changes in cities across the U.S. and Canada.

In the past two years, more than 65 garden retailers, nurseries and landscaping companies, including the two largest home improvement retailers in the world, Home Depot and Lowe’s, as well as Whole Foods and BJ’s Wholesale Club, have committed to take steps to eliminate neonicotinoids. This shift was documented in Greenhouse Grower’s 2016 State of the Industry Survey, in which 74 percent of growers who supply mass merchants and home improvement chains said they will not use neonicotinoid insecticides in 2016.

Several other major retailers, including Walmart, Ace Hardware and True Value Hardware, have yet to make formal commitments to eliminate use of these toxic insecticides in their nursery supply chains.

In order to determine the state of marketplace progress in eliminating bee-toxic neonicotinoid insecticides from bee-attractive plants, we undertook the current study, Gardeners Beware 2016: Bee- toxic Pesticides Found in “Bee-Friendly” Plants Sold at Garden Centers Across the U.S. We worked with 13 organizations in 12 states across the U.S. to sample and analyze 60 plants. Thirteen of these plants were bee-attractive tree or shrub species often used as ornamental street trees in cities and towns. The results of our new report shows that fewer bee-attractive ornamental plants sold at major retailers have been pre-treated with pesticides shown to harm and kill bees.

Findings Include:

  • Comparison of 2016 results to 2013 and 2014 results indicates that progress is being made towards reducing the use of neonicotinoids in ornamental plants; only 23 percent of plants were found to contain neonicotinoids in 2016, compared with slightly more than 50 percent in 2013 and 2014.
  • The results of this study indicate that 14 out of 60 plants (23 percent) tested positive for one or more neonicotinoid insecticides. Concentrations ranged from 1–890 μg/kg (parts per billion or ppb) imidacloprid equivalents.
  • Ornamental flowering trees used in city landscaping — a major source of food for urban and suburban bees — were also tested, with three out of 13 samples testing positive for neonicotinoids. City and county governments, businesses, and landscapers planning new tree plantings could be unwittingly creating sources of pesticide exposure for urban pollinators if the trees they plant have been treated with systemic neonicotinoids.
  • Imidacloprid and its metabolites were found most frequently, with residues of the parent imidacloprid detected in 11 of the 14 (79 percent) plant samples that tested positive for neonicotinoids.
  • Most plants with positive detections contained only a single pesticide; however, two flower samples (14 percent of positive samples) contained two different neonicotinoid insecticides.
  • This observation is consistent with a 2015 survey of nursery growers conducted by Friends of the Earth, Growing Bee Friendly Garden Plants: Profiles in Innovation, which showed that many nurseries are working to meet consumer and retailer demand for neonicotinoid-free plants, choosing biological controls and integrated pest management approaches coupled with the use of lower toxicity insecticides, rather than neonicotinoids.
  • The new study reveals that larger retailers like Home Depot and Lowe’s, which have made commitments to phase out use of these pesticides in their plants and on their shelves, are making significant progress toward that goal.

Adoption of formal policies by garden retailers to eliminate the use of neonicotinoids is considered significant by the general public. A YouGov Poll conducted in 2016 and released in conjunction with this report found that 67 percent of Americans feel more positively about Home Depot and 66 percent feel more positively about Lowe’s because of their formal commitments to eliminate neonics. Following this survey, half of respondents said they are more likely to shop at Home Depot (50 percent) and Lowe’s (51 percent) because of the retailer’s commitment. Further, more than a third (39 percent) said they’d feel more negatively about a retailer that had not formally committed to eliminate systemic neonicotinoid insecticides. 
This study confirms the continuing presence of neonicotinoids in common garden plants sold to consumers at garden centers across the U.S. However, rates of detection are significantly lower compared with rates in our 2013 and 2014 tests. This reduction is likely due to change in store policies that commit retailers to eliminate or phase-out neonicotinoid use on garden plants. Retailer commitments are having a ripple effect in production methods by suppliers and have resulted in reduced use of neonicotinoids in common garden plants overall. While significant progress has been 
made, it is also clear that there is still work ahead to transform the entire supply chain and garden industry to move away from use of bee-toxic pesticides in ornamental plants

For more information, please visit the Friends of the Earth’s BeeAction campaign webpage.

About the Author

Susan Kegley is Principal and CEO of Pesticide Research Institute. She is a PhD Organic chemist with expertise in pesticide chemistry, fate and transport and toxicology of organic chemicals, and U.S. pesticide regulation.