Deadly Gardens

Dead bee (photo from Wikimedia Commons)
Dead bee (photo from Wikimedia Commons)

Today’s important message is late for this year’s growing season but we can always take action right now.

I’m sure you’ve heard about the dangers to honeybees from neonicotinoids, a class of pesticides used heavily in agriculture since 2008.  What you might not realize is that this pesticide may be in your garden whether you put it there or not.  Here’s why.

What are neonicotinoids?

Nicotine kills insects but it breaks down too quickly for modern agricultural use. Neonicotinoids (“neonics”) are chemicals similar to nicotine specially formulated to last a long time.

Neonics are nervous system disrupters that, depending on dose and exposure, cause confusion, hyperactive behavior, severe tremors or death in insects.  Low doses kill slowly through chronic exposure because the chemical lasts so long (5 months to years).

Neonics are “systemic” poisons because they are water soluble.  Plants suck up neonic-laden water and distribute it into roots, leaves, pollen, nectar, everywhere.  The entire plant is poisonous to a wide range of insects including “bad” insects that suck juices and eat leaves (aphids, stinkbugs and Japanese beetles) and “good” insects that collect pollen and nectar (bees and butterflies).  Bees and butterflies visit poisoned flowers and die elsewhere.

How do neonicotinoids get into your garden?

Neonicotinoids are primarily delivered via soil treatments and seed coatings.  Garden treatments contain doses 40 times higher than agricultural products.  These pathways may surprise you.

  1. Pesticides you bought to kill bad insects, especially soil treatments. Check the label!
  2. Potting soil:  If treated with neonics, the plants grown in the soil are poisonous. Check the label!
  3. Plants or seedlings you bought at the store:  They’re already grown, but how? If their seeds were coated with neonics or the soil was treated, the plants you bought are poisonous.

What can you do?

Read the label. Ask questions. Here are the chemical names to look for.
* Acetamiprid
* Clothianidin
* Dinotefuran
* Imidacloprid (fact sheet)
* Nitenpyram
* Thiocloprid
* Thiamethoxam

Practice reading labels:  Many companies have neonic products. This example is from the “Bayer Advanced” product line containing Imidacloprid.  Scroll down below Quick Facts to see Active ingredients.
12-month Tree & Shrub Insect Control
2-in-1 Systemic Rose & Flower Care
2-in-1 Insect Control and Fertilizer

Labels tell you some of the insects the product kills but never all of the insects affected.

Don’t panic.

If you’ve learned something new, don’t worry, don’t blame yourself. Time is on your side. Start now to change your garden.  Remember this Chinese proverb …

The best time to plant a tree was 20 years ago. The next best time is now.


(photo of dead bee from Wikimedia Commons. Click on the image to see the original)


Additional Resources:
A blog for home gardeners: potting soil and nursery plants Skowhegan, Maine, 2013.
News about pesticide-laced potting soil WRAL, Raleigh, NC, 2003.
Backyard Pesticide Use May Fuel Bee Die-offs. WIRED, 2012.
Risk Assessments Are Missing Harmful Effects of Neonics on Honey Bees Union of Concerned Scientists, 2013.
How neonicotinoids affect honey bee queens. Sub-lethal effects. The Journal Nature, 2016.
Bayer sold Bayer Garden and Bayer Advanced product lines to SBM (based in France). October 2016.

6 thoughts on “Deadly Gardens

  1. Kate, thanks for publishing this. I think most people don’t even have a thought about how poisonous these chemicals are, to the entire environment and us. We have rarely even used herbicides on our lawn, only when we were trying to sell our house and wanted the lawn to be “attractive”. We just live with the bad bugs as well as the good. (I truly do hate the emerald ash borer though, and wish we could do something about that bug.) My sister has her lawn treated regularly, and she has 2 dogs that have had lymphoma, even though she keeps them off the lawn for a few days after it’s treated.

    We won’t even use flea & tick killers on our cats, unless we absolutely have to. Last year we got a flea infestation somehow, even though our cats are indoor only, and we did use the flea treatments on them for 2 or three months, but we also flea combed them every day and vacuumed often to get rid of the invaders. I think a lot of our medical issues these days are due to the chemicals that are pervasive in our daily lives.

  2. thank you for your soothing words at the end of the blog. I have been beside myself because apparently big box stores even have neonics in large shrubs, which of course i purchase for the purpose of enticing bees! and who would even look at the ingredients of potting soil!
    The suggestion from the source I read was only to purchase from independent nurseries which guarantee they do not use those products. Apparently the big box stores have pledged not to carry anything with neonic connection after 2019.
    Wow, so even when a person doesn’t use insecticides, they can damage their creatures without knowing it.
    Thanks so much for bringing this to our attention.

  3. Thanks so much for this information. I have conversations with all nurseries where I purchase plants about their use of neonicotinoids and most of our local nurseries are free of them. However, it was my understanding that many of the big box plant sellers were selling plants that were grown with them (Walmart, Lowe’s, etc.) On the positive side, I thought that I had heard that these sellers were going to phase out their sale.

    Recent article (May 2017) by Bob Dailey, garden writer, cited “Bees aren’t the only beneficial insects killed by neonic chemicals. Aphids love milkweed. Growers and nurseries spray milkweed with neonics to prevent aphids. But milkweed is the food source of the monarch butterfly larvae. When the monarch caterpillars hatch and begin eating the leaves, they die.
    Home Depot and Lowes, two major big box stores, have pledged to phase out all neonicotinoids by 2018, and Home Depot has gone as far as to label those plants treated with neonics. However, gardeners need to look closely at the labels.”

  4. Oh NO! I use Bayer products on my roses to fight the aphids. What a dummy I’ve been. Thank you for this Kate, again you have educated me. I appreciate you always closing your posts with something positive.

  5. How long does this stuff last on the plants? I wish I had this knowledge earlier. We just redid our back and front yards which were heavily overgrown. I just hope that the plants we used, some flowering, some bushes and grasses are safe. My butterfly bush is doing well, but now I worry that it may kill it’s visitors. So sad.

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