Spring Flowers, Buzzing Bees, and Nerve Poisons
As the sun comes out to melt the snow and spring planting mania builds, I wanted to share some information about neonicotinoids. If you’re now scratching your head wondering what a neon-icky-tinoid might be, the simple answer is an inorganic, man-made insecticide with very particular traits that make it unacceptably toxic to honeybees and other pollinators. Break down the long scientific name in digestible bits and you have: “new” (neo), “nicotine” (nicotin), “like” (oid). These chemicals are “new” because they’ve only been around since development in the 1980’s and 1990’s and “nicotine-like” because the mode of action is similar to that of nicotine, which has been used as an insecticide for hundreds of years and is what makes a nightshade plant so deadly. “Why create something new when nicotine is found in nature?”, you might ask. Although nicotine is natural and highly effective as an insecticide, it is extremely toxic to farm and nursery workers who come in contact with it, causing death, neurological damage, and cancers. Neonicotinoids were developed as a safer alternative.
Beautiful Death
The beauty of neonicotinoids for production nurseries (companies that produce plants for sale by others) is that they allow the low-cost creation of masses of gorgeous plants with nary an insect-induced blemish. How? By making the entire plant from root to tip toxic to insects for a year or more. That’s all insects. Destructive pest species along with honeybees, native pollinators, butterflies, and other beneficials that come into contact with a neonicotinoid-treated plant are poisoned. Exposed insects either die outright or become permanently impaired and die a more lingering death.
Once a plant is treated with a neonicotinoid, the chemical remains resident in the plant tissues and is carried in sap to new tissues as the plant grows. Neonicotinoids can also remain adhered to soil in which a plant is grown, creating a long-lasting reservoir for further contamination. Their persistence in plant tissues and the ease with which they are carried in the sap of a plant are what make neonicotinoids so valued by the agricultural and nursery industries. But, poisonous neonicotinoid-treated plants clearly don’t belong in your pollinator garden. Unfortunately, though, a majority of the plants now offered for use in home gardens have been treated with neonicotinoids. The big home and hardware stores are getting most of the negative publicity, but it doesn’t matter if you shop at a large box store, a big nursery center, and or a small local nursery—neonicotinoids are almost ubiquitous in the nursery industry and chances are the beautiful perennial you pick up to add to your pollinator garden this spring has been treated.
Confusion Runs Rampant
I’ve seen a swirl of confusion in the media and online concerning neonicotinoids as the outcry grows over the USDA’s continued insistence that they are safe and the EPA’s failure to eliminate their use. Just today I received multiple notices from environmental justice organizations that are suing the EPA over the lack of movement around the use of neonicotinoids and the approval of new insecticides, sulfoxaflor and flupyradifurone, which are not neonicotinoids but have many similar characteristics. To help clear up the confusion and make the “systemic insecticide” or “bee-killing pesticide” furor easier to sort out, I’ve put together a little question and answer session for you. It’s my hope that I might arm you with the information you need to confidently add your voice to the outcry. But if you don’t have time for all the details and want a quick overview instead, skip on down to “Just the Highlights” and the game plan for keeping neonicotinoids out of your garden.
A Little Q and A Session on All Things Neonicotinoid
- How do neonicotinoids kill insects?
- They are neurotoxins that cause paralysis and death. At least one of the chemical companies involved in their development and production also developed “nerve gas” for use on humans during both World Wars.
- Are they toxic to humans and other mammals?
- The news is that they are “less toxic” to non-insect organisms like us. The difference in toxicity is linked to how the chemicals move from an animal’s blood to its brain—every organism on Earth may have neonicotinoids in its bloodstream but it’s easier for these chemicals to move from an insect’s blood to its brain. Unfortunately, some pesky studies on mice are showing that once they break down, neonicotinoids can also be lethal to mammals. It’s important to realize that this class of insecticides is new enough that not everything is yet known about the impacts.
- Do neonicotinoids have other environmental impacts?
- Preliminary research says yes! Studies in Europe have shown impacts on aquatic invertebrates of all types and on non-target insects. European research is also suggesting that bird populations are being reduced dramatically due to substantial reductions in the populations of insects that they depend upon for food, especially while raising young. The use of neonicotinoids has been dubbed an “unsustainable agricultural practice” by many.
- How are neonicotinoids applied to plants?
- Every which way imaginable. They are applied to seeds as a seed treatment, are sprayed on foliage, are applied to soil as granules, and are mixed in irrigation water. Once in the plant tissues, neonicotinoids become persistent in the plant and are carried into new tissues as the plant grows.
- Which insects are killed by neonicotinoids?
- Although sucking insects like aphids, mealy bugs, spider mites, and thrips are most commonly targeted for control, I can’t find mention of any insect that is not killed by this class of insecticides. Honeybees are killed outright or become neurologically impaired and not able to find their way back to their hives. Some may also carry the poison back to the hive, causing or contributing to what has been dubbed “hive collapse”. It’s important to note, too, that neonicotinoids don’t spare native pollinators or butterflies.
Guttation occurs when the heat of the day pulls excess sap out stomata at the edges of leaves. Guttation can expose pollinators and other insects to neonicotinoids that contaminate the sap of treated plants.
How do bees make contact with neonicotinoids?
- Through exposure to pollen and nectar (including that which is brought back to the hive); via exposure to dust (either dry insecticide that is released while treated seeds are planted or insecticide that is adhered to airborne soil); and via exposure to guttation (you know…when sap drops form at the edge of a leaf).
- What crops are treated with neonicotinoids?
- Almost all corn and soybean crops, other grain and cereal crops, sunflowers, safflowers, tomatoes, berry bushes—the list goes on and on to include almost every food crop produced plus nursery stock like trees, shrubs, perennials, and bedding plants. This includes…ready for this?…nursery plants that are marketed as “bee-friendly” or are specifically sold to unsuspecting gardens as pollinator or butterfly plants.
- Aren’t all the pesticides gone by the time I buy those new plants for my pollinator garden?
- No! Neonicotinoids have a half-life of 1,000 days. That means it takes 1,000 days for the concentration of a neonicotinoid to reduce by half in the environment. Almost 3 years just to get it to one-half concentration. Even if the store you bought your plants from didn’t apply any neonicotinoids, those that were applied at the production nursery are still contaminating your plant and the soil in its pot. Most manufacturers of neonicotinoids indicate they will remain residual in a plant for at least a year and up to 2 years. Neonicotinoids are readily carried in sap, so they enter new plant tissues quite readily as a plant grows. That means that simply plucking off the existing blooms from a treated plant won’t protect pollinators that visit new blooms…those new blooms will also be toxic. Remember, that the sap of your treated plant and the pollen are also toxic–any insect that comes into contact with the sap or pollen, even indirectly, can be poisoned.
- Are neonicotinoids widely used?
- Neonicotinoids are THE most widely used pesticides in the world and are used to treat approximately one-third of U.S. crops. They also are widely used in the nursery industry, which produces annuals, perennials, shrubs, and trees for ornamental purposes. They are especially valued in protecting tender greenhouse-grown plants from sucking insects because they are highly effective and deemed safer for nursery workers.
- If they kill bees, why aren’t neonicotinoids banned?
- Because of the potential economic impact in countries where they are used. Since neonicotinoids are so persistent and become concentrated in all parts of a plant, they don’t need to be applied as frequently and are a “one-chemical kills everything” choice. They also spread into new parts of a plant and the plant grows. That makes for cheap and efficient insect control and reduced costs. The tide is turning a bit, though, in Europe where regulations are being put in place to keep neonicotinoids away from crops that are especially attractive to bees and to ensure that seed coatings are adhered well so they don’t enter the air as dust during planting. In the U.S., the Fish and Wildlife Service is taking the lead by eliminating the use of neonicotinoids in the production of wildlife food crops on the National Wildlife Refuges.
- Glyphosate (that herbicide that starts with “R”) is a neonicotinoid, isn’t it?
- Glyphosate is an herbicide that is sprayed on foliage to kill weed plants and is not at all related to the neonicotinoid class of insecticides. Glyphosate and neonicotinoids are used together in the same fields, though–the one to control weeds and the other to control insects–which causes confusion. Adding to the confusion, Monsanto, which produces glyphosate, does not produce neonicotinoids but treats the GMO soybeans it sells with this class of insecticide.
Just the Highlights
To summarize, neonicotinoids are “new nicotine-like” nerve poisons that make all parts of a plant poisonous, move into new plant tissues as a plant grows, kill all insects with which they come into contact (including pollinators), affect aquatic ecosystems, amphibians, and bird populations, may impact humans and mammals as they break down, and are applied on our food and introduced to our water supplies worldwide. And even though neonicotinoids are known to kill bees and persist in plants and on soil for years, that are no regulations in place preventing sellers from marketing neonicotinoid-treated plants as “bee-friendly”, “attractive to butterflies”, or “great for pollinator gardens”.
Get Your Game Plan Here
Ok, now that I’ve completely freaked you out, here’s a game plan for making your yard neonicotinoid-free.
Garden Organically
- Remember that organic insecticides can still kill bees, but they generally do not persist on your plants or in the environment for long. They are a better choice if insecticides are needed, but you really need to understand how to use them properly to reduce impacts on pollinators and other non-target insects. If you’re interested in organic gardening, research it! Rodale Press, Storey Publishing, Mother Earth News, and Timber Press are just a few of the trusted outlets where you can find in-depth instruction in organic gardening. Your local Ag Extension Agent can be a great local source of guidance.
- Read Labels
- Don’t buy or apply products that contain:
- Imidacloprid
- Acetamiprid
- Clothianidin
- Dinotefuran
- Nithiazine
- Thiacloprid
- Thiamethoxam
- Don’t buy or apply products that contain:
- Ask to See the Written Neonicotinoid Policy of Your Nursery
- You’ll want to shop from nurseries that: 1) do not use neonicotinoids themselves; and 2) either grow all their own plants from untreated seed or purchase plants for resale that were growth without neonicotinoids.
- Prairie Moon Nursery, located in Winona, Minnesota, sells plants, seeds, and bare roots online and has a strict neonicotinoid policy that represents what you’re looking for. Read it here. High Country Gardens, located in Colorado, also sells online and has a strong neonicotinoid policy, too.
- Search Out Local Native Plant Nurseries
- Natives to your area are less prone to insect issues to begin with and native plant nurseries commonly adhere to organic growing practices (although you must confirm with each nursery).
- Find native plant nurseries in your state using a directory like the one found on the Plant Native site.
- Plant Seeds!
- It’s much easier to find a wide variety of untreated seed to use in your pollinator garden than it is to locate uncontaminated plants.
- You can find at least a small selection of organic, neonicotinoid-free seed at many of the large seed houses. Look at each seed description to see if it’s marked organic and contact the company with questions.
- Some seed companies make an even bigger commitment to producing and providing organic seed and/or seed that has not been treated with neonicotinoids. You might want to check out companies like Prairie Moon, Seeds of Change, High Mowing Organic Seeds, Baker Creek Heirloom Seeds, Botanical Interests, Peaceful Valley, Renee’s Garden, Seed Saver’s Exchange, and Territorial Seed Company. This list is not meant to be exhaustive as I just grabbed my stack of catalogs from trusted sources to create it.
- Download my free guide to creating and maintaining a neonicotinoid-free garden. Neonicotinoid Free Gardening Guide (1543 downloads)
Add to the Discussion!
I hope I was able to both clear up any confusion you might have had about neonicotinoids and give you a reasonable approach to creating a pollinator garden that’s free of toxic plants. If you have other insights, ideas, or experience gardening around the neonicotinoid issue, I would love to hear from you in the comments below.
I just wanted to thank you for writing one of the easiest to understand articles I have ever read on this subject. I have shared it several times with everyone I know. Hopefully we can all work to get neonics banned in the US! Thank you!
Thank you so much for your feedback, Seah. I wanted very much for this to be understandable because I was feeling that we were all being swirled around in confusing technical terms and “half-information” on the subject of neonicotinoids. I’m so grateful to hear that it was an easy read. I knew I had to write this article when I realized people were confusing the impacts of neonics and glyphosate. Thanks so much for the shares–it’s so very important to get this information out there so that people understand they are not powerless against the big chemical companies. We can all buy organic, plant organic, share information, speak out, and support companies and organizations who are walking the sustainability talk.
I would caution everyone to a very careful reading of the neo-nicotinoid statement from High Country Gardens. I know they are trying, but the specify only their seeds to be free of neonics. Their earlier statement (which has changed within the last few months) had said that in cases where their suppliers had to use neonics, that they were careful to keep the chemical away from bees during application. But as we know, that is not the problem; it’s the product’s persistence endangering bees for years as the plant continues to grow and flower in our gardens. I have asked High Country Gardens in December 2018 whether they could guarantee particular neonic free plants, and have not received a reply.
Hi Margaret, I actually looked into this since I recently ordered some plants from High Country, and their live perennial plants, as well as wildflower seeds, are untreated. I can see how the statement would read though as only seeds. They did tell me though that bulbs and bare root plants that they get from Holland may have residual neonics on them.
On March 18, 2014, the Dutch Parliament voted to ban all neonicotinoid pesticide uses in the Netherlands. This means that any bulbs sourced from the Netherlands (Holland) since then would be free of these pesticides. For more information go to https://www.ontariobee.com/inside-oba/news-and-updates/dutch-parliament-votes-to-ban-all-neonicotinoid-pesticide-uses-in-the-netherlands.
That’s great! I’ll get this article updated by the end of the week. Other positive things have also happened since I first posted it.
Thank you! I am trying to be friendly to the planet and help our pollinators!
You’re welcome, I’m so glad you found the article.
Oh, God! Thank-you so much for this. I specifically planted only plants that will help the local pollinators in my area, Vancouver Island. I had no idea that neonicotinoids worked like this. I don’t use any chemicals at all, so I thought I was safe. Now I feel sick.
You might want to go back to the store and ask to see their policy. If they were plants you bought this year, you might even ask if you could return them if they tell you they have no policy or that they use neonicotinoids.
Are you familiar with seedles. Do you know if they are safe?
Thanks for your question. I checked into that for you and found that Seedles provides this written policy, “Seedles policy is not to buy any seeds treated with neonicotinoids”. For anyone not familiar with Seedles, it’s a small company in California that creates “seed bombs” using regionally appropriate wildflower seeds. The seeds are encased in little balls of clay, compost, and worm casings that can be tossed into disturbed areas to create a bit of pollinator habitat. The company is specifically concerned with helping pollinators.
Thanks Linda shall be circulating this amongst friends family and school!
I’m so glad you found the article helpful, Sarah, and are passing it on. It’s such important information as people get ready to garden this spring.
Hi Linda, thank you so much for your crusade against this deadly chemical.
I manage a local garden center that has a large nursery, which grows the majority of the trees, shrubs, and perennials that we retail.
I am having such a difficult time with my conscious, and the marketing with which they use to sell their products. They are constantly applying
this deadly product to everything that grows, on the combined 20+ acres of property while promoting, “pollinator and environmentally friendly” plants. When voicing my concerns, they look at me as if I’m crazy and reply with “the cost of doing business” and or “the alternative is too costly”, Really!!!!!
I just found your article, site, today and want to give you BIG thank you!!! I will be sharing with many, over and over…..
God Bless and thank you so much for sharing!
I have lived on a small lake in suburban Minneapolis MN for over 20 years. The bees and butterflies have dwindled to almost nothing. This year is the first time I noticed the deathly silence at night. We usually hear tree frogs singing at night, and this year, nothing. Not even a cricket, just absolute silence.
I am now more convinced than ever that this is a result of neonicotinoid insecticides being used in our neighborhood. Back in the 60’s, they got the great idea to drain all the water from the streets directly into the small neighborhood lakes and then into the creeks to prevent flooding. All the chemical runoff goes directly into our lakes and rivers. I am so sad Linda. Thank you for writing this excellent article. I will share with others.
I have a question. I have planted Vinca major for many years because the deer do not like to eat it. Now I am afraid to do so because I don’t know where to buy any bedding plants without neonics. We only have Home Depot and Lowes and a local nursery which doesn’t know anything about neonics in their plant offerings. How can I have plants this summer?
Definitely start by asking Home Depot and Lowes about their current progress in terms of phasing out neonics. Both made announcements last year about plans to phase them out. Also, check out mail order options, including the ones I have listed in this post. Many of these companies sell plants, as well as seeds, and you might be able to source what you want that way. All my best for a lovely yard this year!
I still have to be very careful where I purchase my plants. A very large nursery by me assured me that everything in their greenhouse was neonic free and that I should shop with confidence. I later talked to the buyer, who told me that nothing is neonic free because they make more money selling perennials that are pretty rather than native. I now only buy plants grown by American Beauty, the only native plant distributor in my area. So sad.
thanks so much for the wonderful article that clarifies our concerns.
You’re very welcome.
I am needing a short and sweet memo to hand to nursery managers about neonicotinoids. You write well. Can you supply me with something?
I have already begun fhe process of asking some nurseries to not buy from growers that use neonicotinoids.
And also, bulbs are also not to bee trusted unless organic.
I’m glad you enjoyed the post. You might want to download the one-page summary I reference to share with nursery managers. Feel free to modify it for your specific needs. All my best to you!
I want to thank you so much for your article.
I work at a Home Depot and they do require any suppliers who use neonicotinoids to label each and every pot. I have been trying to educate others about the dangers of neonicotinoids for a little over a year now.
I would like to print your summary and share it with management and others.
Thank you, again. I will be sharing this article with many others. We have a large butterfly and bee gardening community in my area who will also be more than happy to read and share your article.
Sincerely,
Liz
Thank you for your feedback, Liz. I’m glad you found my post helpful and I’m happy to hear that Home Depot requires labeling of neonic-treated plants. I just added a link near the bottom of the article that will allow you to download the summary in PDF format for easier printing. I think it’s great that you’re spreading the word. Happy bee-safe gardening!
Dear Linda,
Thank you so much for your helpful article.
I am having the same trouble here in England and have found only one supplier that I trust to fill my wild life garden.
I am shouting loudly and won’t stop until the government ban the madness.
Thank you again.
You’re very welcome. I was just thinking earlier today that the neonics issue seems to have been forgotten. I’m glad you’re still shouting loudly for a ban.
Dear Elaine,
Could you please put on the name of the supplier? I had no idea plants were being poisoned at source as seeds or prior to sale. I was under the delusion that my garden was pesticide free. I have two packs of wild flower ‘bombs’ not yet planted, and now worried about planting them (Lidl purchase).
Excellent article! Years ago, I bought a small rose bush from Home Depot. When I got home and went to plant it, a label fell out informing me that it was “protected” with neonicotoniods! I thought “What harm can one plant do in a 1/2 acre organic garden?” I got my answer: within a day and a half, I started finding dead and dying bees everywhere!!! I immediately cut off all flowers and returned the plant, but the damage was done. I’d rather have bare dirt than kill off our endangered bees. (But I will look into the companies mentioned above)
Linda, thanks for the overall article and the very useful one-page summary on avoiding neonics. May we have your permission for our New Jersey Butterfly Club to distribute the summary as a handout at our presentations and table events, along with our other educational materials? We may also want to link to it from our website.
Yes, you may certainly copy and distribute the summary, and link to the article. I’m very pleased that you find it useful.
I’ve noticed this spring that the big box stores are being a bit more stealth in their labeling. They’re not touting the fact that their plants are treated with wonderful long-acting insecticides, but instead are including a vague warning about the plants being toxic to humans and animals. Toxic pansies weren’t quite what I was looking for in my wildlife garden, so they stayed at the store.
I’ll be posting a new series of gardening and environmental articles this year, so may have more content soon that will be of interest to your members.
Thank you so much. My daughter and I started butterfly gardens last year and are now ripping out the plants we bought commercially (except for our native plant sale items)..
‘Sick’ is the best word to describe how we feel after reading your article but we are so grateful to have this information. You have done a great service writing this article and allowing everyone to share it. Bless you.
Monrovia Nursery no longer uses neonicotinoids on any of its plants.
Thanks for pointing this out–it’s great news. They’re now producing their plugs with no neonics. The only caution I’ve seen is to make sure the Monrovia name is on the finished plant you buy. A Monrovia plug can still be grown up by a different company that uses neonics later in the process, so look for plants for sale that are clearly branded “Monrovia”.
Thank you so much for your very informative article. Yesterday I planted a grape vine that I purchased at Home Depot. It wasn’t until after I planted it that I noticed a little piece of plastic in the pot that said it had been treated with neonicotinoids. I have been so careful over the years in planting my organic garden. As it is the end of September my 5′ tall vine only has leaves. I am concerned now that once it produces flowers in the spring that those flowers could be toxic to bees and butterflies. Should I remove the flowers? I would appreciate any advice.
Sorry to hear about your grape vine problems. I would actually dig the plant up and return it, while definitely telling the store why. If Home Depot won’t take it back, I’d bag it and throw it out in the trash (don’t compost it). The reason being, the leaves and other plant parts are also poisonous. I’ve read some new articles recently that detailed the impacts of neonics on birds that are exposed to contaminated insects and plant parts. I’ll write a follow-up article to share that information.
I just about did the same thing. Bought a jujube tree from homedepot. Luckily noticed their microscopic neonicotinoid tag. I want to start a weekend group to wave signs around informing people what they are selling.
Thank you so very much for this concise and easy to understand article. Your public service here is enormous. Thank you. Thank you. Thank you.
You’re very welcome. I’ll be updating this article soon and will be making regular blog posts going forward on related topics. Focus areas will be pollinators and also the creation of fully functional wildlife habitat on residential properties with a focus on birds.
Last night, I was researching “plants for bees” to get some fresh ideas and came across a 2014 article by Wired (How Your Bee-Friendly Garden May Actually Be Killing Bees) which was my 1st introduction to neonicotinoids. I spent the rest of the evening researching and actually had a good long cry at one point – I really feel duped that I have been an unwitting contributor to this problem. I found your article this morning and especially appreciate that you have left the post open for continued updates and your list of non-neonic sources. At the moment, I am only going to buy from Home Depot as it appears they do label what few plants contain neonics and plan to try out the on-line sources you list. I will show this to my sister who has been gardening longer that I, and has over the last few years mentioned that she sees fewer bees and butterflys. Thanks again for a well-written article that also pointed us in the direction of what we can to to keep neonics out of our own yards.
I’m glad you found my article. I’ve been really pleased that so many people have stumbled upon it. And I do need to update it again. The Sierra Club recently reported their success in getting some of the chemicals banned. Some are still in use, but several are not (but you’ll still need to be on the look-out for tags and/or will need to ask stores about their policy.)
Hmmm thanks so much for this enlightening article. Taking my poisonous jujube tree back to homedepot. Feel like killing it and leaving a big warning sign “danger environmental hazard” on it. Glue it to the ground in front of the home depot GARDEN center.
You’re welcome. I’m glad you found it. I need to take some pics of those tags and post them. I almost bought a pansy last year at Lowes and then saw the tiny tag indicating the plant was not safe for human consumption. Since pansy flowers are usually edible, it felt like a serious issue.
Thank you for this in-depth article! I am so distressed as I planted a pollinator-friendly garden that I am now worried is going to kill them. 🙁 I also see “not safe for human consumption” on the tags from Lowes–does that indicate that it contains neonicotinoids??
Hi Averyl, The answer is probably yes, the plants have been treated with neonics. Lowes, in particular, has a convoluted history with neonics. In 2015, they promised to phase them out by 2019, but hedged their bets by making their elimination dependent on the availability of “suitable alternatives.” Ask any grower and they’ll claim there are no suitable alternatives to neonics. Consumers want cosmetically perfect plants, and the only way to keep plants looking perfect is to poison all the plant parts with systemic insecticide, in other words, to treat them with neonics. Since I wrote my article, overall presence of neonics in some plants (especially trees and shrubs) seems to be trending down but I can’t find a statement anywhere announcing their elimination from plants sold by Lowes. Lowes is, however, adding those tags advising humans not to eat their plants. You’ll even find those tags on normally edible flowering plants, such as pansies. Just a few weeks ago, my neighbor showed me a plant tag (I don’t think it was from Lowes) that included a convoluted, vague suggestion of some hazard associated with the plant. The wording put the onus on the consumer to exercise caution, but it was entirely unclear if a hazard actually existed, what it might be, and what kind of cautious activity was due. When I see any such wording on a plant tag, I leave the plant on the shelf and stand by my recommendation to grow your own pollinator plants from untreated seed.
Thank you. This is awful.
I have shared your article on Facebook and may do a blog post. Again, I appreciate your time, research and sharing!
Thank you so much for this information. As heartbreaking as it is to hear, knowledge is power. One thing I’m still not 100% clear about after having read your article twice is this: If I recently (and unknowingly) planted perennials treated with neonics and I remove these plants entirely from my garden, top growth and root ball, is that sufficient? Or do I also need to be concerned about the remaining soil that came in contact with the neonic-contaminated root ball? Will that remaining soil contaminate new plantings?
From what I understand, you should be okay, especially if you removed the potting soil that was surrounding the roots. Neonics characteristically bind tightly to organic soils with high organic matter. Potting soils are almost all organic matter, so the chemical would have been bond tightly and wouldn’t have had a high tendency to leach out into your surrounding soil. Here’s a scientific article that might be helpful. The authors studied applications of chemical to plants already in the ground, but the concepts would be similar to what might happen with chemical that’s added to the environment in treated potting soil. They found that neonics will leach through sandy soils, but was bound up in soils that contained more organic matter. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4284396/
I ordered wildflower seeds from American Meadows to plant in my beautiful garden and just checked and their seeds are neonicotinoid free. Thanks for this article. I will avoid buying from the big box stores.