Like many of you, I find the statistics on pollinator declines distressing. More than a quarter of our native bumble bee species are at risk of extinction. Monarch butterflies have seen an 80 percent decline in the eastern U.S. and a 74 percent decline in the West. It’s painful. I care about those bees and butterflies, sure. But I also care about the humans who are sustained by the ecosystem services those pollinators provide.
So a few years ago I did the good deed of picking up some milkweeds at my local garden center and planting them in my backyard, knowing monarch butterflies depend on milkweeds for survival. Yay me, right?
What I didn’t know is that monarch caterpillars can be harmed when the milkweeds they feast upon contain neonicotinoids, a kind of pesticide. Had my milkweeds been laced with neonicotinoids? I didn’t know enough at the time to ask the garden center staff. And even if that retailer had never applied the stuff, it’s quite possible the nursery from which they sourced their plants had.
Ouch. So much for my lofty intentions.
What Are Neonicotinoids?
Neonicotinoids are a synthetic form of nicotine and the most widely used group of insecticides in the world. They’re applied in a variety of ways, including by spraying foliage, drenching soil, injecting trunks, infusing irrigation water and coating seeds. Tens of millions of acres of neonicotinoid-coated seeds, for example, are planted each year in the U.S. and Canada. Among a multitude of agricultural uses, many commercial nurseries apply them liberally on the ornamental plants that end up in our garden centers and ultimately in our yards. Those same stores also sell them to us in spray bottles from the shelves of their pest control departments.
Once introduced to a plant, neonicotinoids spread to the stems, leaves, fruit, pollen and nectar. They’re highly toxic, even in small quantities, to many invertebrates, including beneficial insects such as bees and butterflies. They’re also long-lasting. So a bumble bee or butterfly who visits a plant that had a neonicotinoid applied even weeks beforehand could still get a toxic dose. The chemicals also persist in the soil, causing plants to inadvertently slurp them up for months or years. Once they’re in soil, they migrate to water bodies, where they hang around and spread further.
This three-minute NRDC video provides a bit more information on “neonics,” as they’re also called, and their disastrous impacts.
An extensive 2016 study by the Xerces Society found that neonicotinoids can kill bees on contact soon after an application. In addition, sublethal doses can impede bees’ ability to forage, find their way home, fight off diseases, avoid predators, and reproduce – all of which can affect long-term survival.
They’re considered a leading cause of massive bee and pollinator die-offs around the globe.
Back to those milkweeds I so virtuously planted in order to save the monarchs. In 2022, researchers collected leaf samples from 235 milkweed plants purchased at 33 retail nurseries across the US. The findings were depressing. They detected an average of 12 pesticide compounds per plant, many at levels known to have adverse and possibly lethal effects on monarchs. Surprisingly, milkweeds with labels touting their wildlife value had just as many pesticides in them as those not bothering to market their ecological bona fides.
In other words, dangerous pesticides – including neonicotinoids – are pervasive throughout the horticulture industry, even in plants branded as “pollinator-friendly.”
So What’s a Well-Meaning Gardener to Do?
Unless or until neonicotinoids and other pesticides are regulated more sensibly, the responsibility falls to us as consumers to protect our home wildlife habitats.
Avoid using any pesticides around your home. Instead, seek out alternative or non-chemical options, which will often resolve the problem at its root rather than simply providing a short-term fix.
Ask your garden center to stop selling pesticides containing neonicotinoids and to stock more ecologically sound options instead.
Ask your garden center if their plants—especially species that support pollinators — have been treated with neonicotinoids at any point in their lives. If the answer is "yes" or "I don’t know," take your business elsewhere.
Patronize nurseries that specialize in native plants. Those folks are likely to use organic practices and know the provenance of their inventory.
If you employ landscape professionals, insist that they use pesticide-free practices and plants.
Bees' Keys, the musical portion of our program, seeks to avoid repetition of artists. Exceptions are sometimes required, though. In the name of science. Tom Petty was featured two weeks ago and now he's being summoned again. Turns out no one else offers quite the same musical motivation to swear off neonics for good.
If you live in the DC vicinity and could use assistance with sustainable landscaping, visit Bees’ Knees Design. I’d be happy to help you.
Resources
Christopher A. Halsch, et al, “Milkweed Plants Bought at Nurseries May Expose Monarch Caterpillars to Harmful Pesticide Residues,” Biological Conservation, September 2022.
Jennifer Hopwood and Matthew Shepherd, “Neonicotinoids in Your Garden,” Wings, Xerces Society, Fall 2012.
“How Neonicotinoids Can Kill Bees,” Xerces Society.
Courtney Lindwall, “Neonicotinoids 101: The Effects on Humans and Bees,” NRDC, May 25, 2022.
“Understanding Neonicotinoids,” Xerces Society.
Thank you for calling this to our attention. Fertilizers and pesticides in one for or another, will bite us right in the bustle if large grower and industry farming continues on this same path they've taken for so long. Small, indi farms/growers seem to be the best direction- as they know exactly how they have to behave if they're going to stay afloat and succeed. More people are becoming aware. But dangitall progress is so slow-- when folks' paycheck relies on them ... being one of the see, hear, speak no-evils.
I think you are being too generous. You won't get a straight answer from garden variety nurseries. Know who you are dealing with and what they really care about. There are more and more native plant nurseries to choose from. And thank you spreading the word.