Pesticides found in ‘bee-friendly’ plants at garden centres

Maria Leung —

A new study by Friends of the Earth Canada shows that over 60% of “bee-friendly” home garden plants sold at garden centers have been pre-treated with neonicotinoids (neonics) pesticides shown to harm and kill bees. Of the samples collected from London, 100% contained neonics, the highest amount in the Canadian tests.

The plants tested were: Calibrachoa, Gerbera Daisy, Shasta Daisy and Zonal Geranium. All but the Zonal Geranium showed two neonic pesticides, increasing its sub-lethal effects.

The Canadian data is part of a larger study, Gardeners Beware 2014, released by Friends of the Earth in Canada and Friends of the Earth U.S. with Pesticide Research Institute (PRI). Garden plant samples were collected from top garden retailers from 18 cities across Canada and the United States. Canadian samples were collected in London (Ontario), Montreal (Quebec) and Vancouver (British Columbia).

Gardeners Beware 2014 reported that 51% of the total samples contain the bee-killing neonicotinoids. Some flowers contained neonic levels high enough to kill bees outright (assuming comparable concentrations are present in the flowers’ pollen and nectar). Further, 40% of the positive samples contained two or more neonicotinoids.

“The results of this study are profoundly upsetting,” said Maureen Temme, a lifelong gardener, who collected and prepared the plant samples from London. “We gardeners, try to purchase bee-attractive plants for our home gardens because we know that honeybees and native bees are assaulted by habitat loss, diseases and pests, and agricultural neonicotinoid use. It is shocking to realize that plants purchased at garden centers might make our own gardens toxic to bees!”

“The high percentage of contaminated plants and their neonicotinoid concentrations suggest that this is a widespread problem,” said Beatrice Olivastri, CEO, Friends of the Earth Canada. “Most gardeners have no idea their gardens may be harmful to bees. We’re circulating a petition calling on retailers to get neonicotinoids out of their plants and supply chain as soon as possible. Until then, gardeners should buy organic plants to ensure the safety of bees.” A majority of the UK’s largest garden retailers, including Homebase, B&Q and Wickes, have already voluntarily stopped selling garden products containing neonics.

In addition to pressuring retailers to stop the use of neonicotinoids in their supply chains, Friends of the Earth Canada is calling for Health Canada and Canada’s Pest Management Regulatory Agency (PMRA) to suspend the use of neonicotinoids in Canada as the European Union has in agricultural applications.

“PMRA is providing a loophole for retailers to avoid the cosmetic pesticide bans in provinces like Ontario,” observed Olivastri. “PMRA permits the use of neonicotinoids in horticulture including plants destined for garden centres as a ‘minor use’.” 
High doses of neonics have been responsible for several high profile bee kill offs in Canada. However, even with doses far below the lethal dose of neonics, a strong and growing body of science shows that the pesticide contributes to impairment in bee reproduction, learning, memory, hive communications and immune response. In Gardeners Beware 2014, all garden plant samples where neonics were detected have the potential to harm or even kill bees.

“Our data indicate that many plants sold in nurseries and garden stores across Canada and the U.S. are being pre-treated with systemic neonicotinoid pesticides, making them potentially toxic to pollinators,” said Timothy Brown, Ph.D., co-author of the report from PRI. “Unfortunately, these pesticides don’t break down quickly so these flowers could be toxic to bees for years to come.”

“I want to thank our volunteer gardeners for donating their time and effort to collect the garden flower samples,” said Olivastri. “Without their help, Friends of the Earth Canada wouldn’t have been able to participate in the study.”

Gardeners Beware 2014 is a follow up to a first-of-its-kind pilot study, Gardeners Beware 2013, released by Friends of the Earth U.S. last August. The new study includes more samples, sample purchase locations, and assessment of the distribution of neonicotinoid distribution between flowers and the rest of the plant.

For testing results for each province, please see the charts below.

The Report Gardeners Beware 2014: Bee-Toxic Pesticides Found in “Bee-Friendly” Plants Sold at Garden Centers in the U.S. and Canada, tips for consumers, the petition and a complete list of the co-releasing organizations and cities where plant samples were gathered can be found at . Because of the late spring and sampling deadlines, Home Depot in Canada was the only “chain” retailer with flowering plants available and therefore sampled for Canadian sites in the study.