Nursery plants contain pesticide harmful to bees, study finds

Bees are critical pollinators that have been in decline in recent years.

How can we help the bees?

During my recent research for a column about bees, an expert told me that people who buy plants from garden centers should ask if the plants have been treated with neonicotinoids — a pesticide that has been implicated in honey bee declines.

I was incredulous. Garden center plants are routinely treated with this stuff?

Apparently so. On Wednesday, the environmental advocacy group Friends of the Earth released the results of a study finding that 7 of 13 types of garden plants purchased at top retailers in Washington D.C., the San Francisco Bay Area and Minneapolis contain the pesticide.

They found neonicotinoids in tomato plants, gaillardia, daisies and a plant often planted to attract bees — salvia.

I would imagine even this small snapshot raises a red flag.

“Our investigation is the first to show that so called 'bee-friendly' garden plants contain pesticides that can poison bees, with no warning to gardeners,” said Lisa Archer, director of the Food and Technology Program at Friends of the Earth, in a press release.

The study was co-authored by the Pesticide Research Institute.

The researchers said that the high percentage of contaminated plants and their neonicotinoid concentrations “suggest that this problem is widespread, and that many home gardens have likely become a source of exposure for bees.”

“Unfortunately, these pesticides don't break down quickly — they remain in the plants and the soil,” said Timothy Brown, Ph.D., of the Pesticide Research Institute.

For how long? Rachael Winfree, the Rutgers bee expert who gave me the tip about asking for pesticide-free plants, told me that “people don’t fully know the answer to that. In the body of the plant, probably weeks to months. In trees, it can last over a year. Herbaceous plants in the garden store, at least weeks. In soil, it can last for years.”

Here’s a link to the report.

And here’s a McClatchy News story about the report.

Meanwhile, the U.S. Environmental Protection Agency earlier today that it had developed new pesticide labels that prohibit use of some neonicotinoid pesticide products where bees are present.

“Multiple factors play a role in bee colony declines, including pesticides. The Environmental Protection Agency is taking action to protect bees from pesticide exposure and these label changes will further our efforts,” said Jim Jones, assistant administrator for the Office of Chemical Safety and Pollution Prevention, in a press release.

The new labels will have a bee advisory box and icon with information on routes of exposure and spray drift precautions, the agency said.

More on the EPA's label changes and pollinator protection efforts are here.