Page 1
Nursery Stock Report
Nursery stock labeled as beneficial to pollinators
625 Robert Street North
Saint Paul, Minnesota 55155
Phone: 651-201-6080
www.mda.state.mn.us
03/01/2020
This document is made available electronically by the Minnesota Legislative Reference Library
as part of an ongoing digital archiving project. http://www.leg.state.mn.us/lrl/lrl.asp Page 2
Table of Contents
Executive Summary……………………………………………………………………………………………………………………………3
Background………………………………………………………………………………………………………………………………………..4
Sample Analysis Results…………………………………………………………………………………………………………………….. 6
2015……………………………………………………………………………………………………………………………………….6
2016……………………………………………………………………………………………………………………………………….8
2017……………………………………………………………………………………………………………………………………..11
2018……………………………………………………………………………………………………………………………………..14
2019……………………………………………………………………………………………………………………………………..16
Summary….………………………………………………………………………………………………………………………………………19
Pursuant to Minn. Stat. § 3.197, the cost of preparing this report was approximately $ 6 ,840.
In accordance with the Americans with Disabilities Act, this information is available in alternative forms of communicati on upon request by calling
651-201-6000. TTY users can call the Minnesota Relay Service at 711. The MDA is an equal opportunity employer and provider.
Page 3
Executive Summary
This report is submitted pursuant to 2019 1
st
special Session Minnesota Laws Chap. 88 Art.2, Sec. 22.
By March 1, 2020, the commissioner of agriculture must report recommendations to the
members of the legislative committees or divisions with jurisdiction over agricultural policy
regarding the regulatory oversight of nursery stock labeled as beneficial to pollinators. The
report must include a summary of the Minnesota Department of Agricultural’ s technical ability to
test for insecticides on different parts of plants that comprise nursery stock, including minimum
detectable concentrations for various insecticides, and the cost per test.
Over the past five years, 209 samples advertised as beneficial to pollinators were collected and
analyzed for the presence of systemic insecticides. Of the 209 samples, 24 individual or 11.4% tested
positive at or above the “No Observed Adverse Effect Level” (NOAEL). Of those sites with positive
results, follow-up tests in the subsequent year resulted in no new positive results or no plants
advertised as beneficial to pollinators. All plants remaining from lots testing positive for pesticides
were held off-sale pending relabeling or redaction of any specific claims to the benefit to pollinators,
and official Notice of Violations were issued from the Minnesota Department of Agriculture (MDA).
The MDA Laboratory Services Division worked to verify the quantitative method for detecting five
neonicotinoid insecticides (acetamiprid, clothianidin, dinotefuran, imidacloprid and thiamethoxam) on
flowers. Using the same analytical method for each of the five chemicals, the MDA Lab was able to
verify that the analysis detected each chemical at the level of one part per billion (ppb) as anticipated.
As part of this report, the MDA Lab determined a cost per test to analyze flowers and plant parts for
presence of systemic insecticides. While calculating the incremental cost for an individual sample is
straightforward, the MDA Lab lacks the needed number of analysts during the peak pesticide residue
testing season to process nursery samples along with other required analysis. Due to the complex
nature of the analysis, competition for equipment, and analysts performing their primary program
activities, an investment in base infrastructure would be needed to have the nursery flower sample
analyses performed routinely by the MDA Lab. The Lab has estimated that one analyst could test
approximately 260 samples if they were dedicated to the program. Factors such as salary, supplies,
equipment repair/maintenance, and indirect costs were factored into this estimate . In order to run 260
samples per year, the MDA Lab estimates it would need $155,400 annually, or roughly $600.00 per
sample. Due to these cost and workflow concerns, the MDA began using a third party lab to provide
these analyses in 2017. The third party lab charges $375.00 per sample and has the capacity to process
about 200 samples in a calendar year. The third party lab is able to provide a similar level of accuracy in
detecting these chemicals. Based on these considerations, the current practice of having nursery
flower samples analyzed by a third party lab seems to be the most economical and practical option
going forward.
This report will show that the percentage of samples that have been found in violation has decreased
over the past four years. This decrease has occurred even though the reporting levels for samples in
violation has also decreased as new information has become available from the U.S Environmental
Protection Agency (EPA). The experience of the Minnesota Department of Agriculture in enforcing this
law is that plants that are in violation typically have concentrations well above the EPA NOAEL for
honey bees which would indicate that the current thresholds in place for reporting are adequate. Page 4
Background
In 2014, the Minnesota Nursery Law was amended t o include language to protect pollinators from
systemic insecticides:
18H.14 LABELING AND ADVERTISING OF NURSERY STOCK
(e) A person may not label or advertise an annual plant, bedding plant, or other plant, plant material,
or nursery stock as beneficial to pollinators if the annual plant, bedding plant, plant material, or nursery
stock has been treated with and has a detectable level of systemic insecticide that:
(1) has a pollinator protection box on the label; or
(2) has a pollinator, bee, or honeybee precautionary statement in the environmental hazards
section of the insecticide product label. The commissioner shall enforce this paragraph as provided in
chapter 183.
In response to the new law, the Minnesota Department of Agriculture ( MDA) Plant Protection Division,
the Lab Services Division, and the Pesticide and Fertilizer Management Division worked to develop
standard operating procedures for sampling, lab analysis, and educational outreach materials. MDA
Nursery Program inspectors began educating clientele and distributing a fact sheet on the law as part
of their standard operating procedure when the law went into effect on July 1 , 2014.
Based on the Environmental Protection Agency’s (EPA) review of neonicotinoids and MDA Pesticide
and Fertilizer Management Division information on widely used systemic insecticides , five systemic
neonicotinoids were selected for analysis: acetamiprid, clothianidin, dinotefuran, imidacloprid, and
thiamethoxam. These five insecticides were chosen because they are among the most commonly used
neonicotinoids in Minnesota and methods for analysis a re available. In the fall of 2014, the MDA
Laboratory Services Division began verifying a quantitative method for detecting these five
neonicotinoid insecticides.
During the 2015 Legislative Session, the Minnesota Legislature amended Chapter 18H.14 to read as
follows:
18H.14 LABELING AND ADVERTISING OF NURSERY STOCK
e) A person selling at retail or providing to an end user may not label or advertise an annual plant,
bedding plant, or other plant, plant material, or nursery stock as beneficial to pollinators if the annual
plant, bedding plant, plant material, or nursery stock has:
(1) been treated with a systemic insecticide that:
(i) has a pollinator protection box on the label; or
(ii) has a pollinator, bee, or honey bee precautionary statement in the environmental hazards
section of the insecticide product label; and
(2) a concentration in its flowers greater than the no observed adverse effect level of a systemic
insecticide.
The commissioner shall enforce this paragraph as provided in chapter 18J.
(f) For the purposes of paragraph (e):
(1) "systemic insecticide" means an insecticide that is both absorbed by the plant and translocated
through the plant's vascular system; and
(2) "no observed adverse effect level" means the level established by the United States
Environmental Protection Agency for acute oral toxicity for adult honeybees. Page 5
The MDA revised fact sheets and web information per the new statute and t he Lab Services Division
completed development of specific residue tests for floral material for the five systemic insecticides.
Nineteen samples of plant material were collected during the 2015 nursery inspection season to
support the methods development. The samples were prepared using AOAC (Association of Official
Analytical Chemists) International Official Method 2007.1, and the analysis was performed using a High
Resolution/Accurate Mass Liquid Chromatography-Mass Spectrometry ( HR/AM LC-MS) instrument.
This method was also used in the Friends of the Earth publication { Gardeners Beware 2014: Bee-Toxic
Pesticides Found in “Bee-Friendly” Plants Sold at Garden Centers Across the U.S. and Canada} from
2014. The method was originally developed for pesticide analysis in fruits and vegetables, so it needed
to be verified for use in flowers. The MDA Lab successfully verified the method at the Method Limit of
Quantitation of five parts per billion (ppb) and was determined to be adequate based on the EPA’s
established oral “ No Observed Adverse Effect Level” for the five pesticides.
The EPA defines “No Observed Adverse Effect Level” as, “the highest exposure level at which there are
no biologically significant increases in the frequency or severity of adverse effect between the exposed
population and its appropriate control; some effects may be produced at this level, but they are not
considered adverse or precursors of adverse effects.”
During the 2016 nursery inspection season, 55 flower samples were collected and submitted for
analysis by the MDA’s Lab Services Division. However, due to the high volume of pesticide analysis that
occurs during the growing season, the nursery sample analyses were not completed until fall. Positive
samples were found at three locations, but all plants were gone by the time the results were available.
Still, those sites were notified of the violations which had occurred.
Because of the delay experienced during 2016, the MDA identified a third party lab, Legend Technical
Services, Inc. in St. Paul, who could provide the same analysis, and samples were taken there in 2017.
Legend Technical Services was able to provide a sample analysis turnaround of less than two weeks
throughout the nursery inspection season which is quick enough for labeling to be changed when a
positive sample is found.
In 2015, some companies expressed interest in making special claims (grown without insecticides,
pesticide-free etc.) regarding some of the plants they wanted to sell. It was determined that labeling
statutes allowed such claims provided the company submitted a plan to the Commissioner of
Agriculture describing plant production, handling, and labeling and the plan was approved by the
Commissioner. To formalize this process, a Compliance Agreement template was developed. Upon
request a company interested in making special claims for their plant material received a C ompliance
Agreement template to review. On a case-by-case basis, programs were reviewed by the department
and, if acceptable, a formal Compliance Agreement was drafted, and signed by the company and
department. Several firms requested and entered into these agreements with the department starting
in 2016.
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Sample Analysis Results
2015
MDA Nursery Program inspectors collected 19 samples for systemic insecticide analysis by the MDA
Laboratory Services Division during 2015. An official sample consisted of 20-50 grams of flowers
collected from the same species of plant from the same supplier at one retail sales location. Each
sample was tested for acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam
adapting a laboratory procedure that yielded a result consistent with the “N o Observed Adverse Effect
Level” (NOAEL). No samples taken in 2015 tested at or above the NOAEL for honeybees as those values
were defined at that time by EPA for acute oral toxicity (Table 1).
Samples were taken from plants advertised (labeled, signed, etc.) as pollinator friendly. Examples of
advertising includes pictures or symbols of butterflies, hummingbirds, and bees as well as claims that
the plants are attractive to pollinators, bee friendly, and safe for honeybees (Figure 1).
Table 1. Analytical results for plant samples collected during 2015. No samples were found with
concentrations greater than the levels indicated.
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Anoka MDA Rudbeckia / Black-Eyed-Susan < 5 < 9 < 30 < 15 < 20
Anoka MDA Monarda / Bee Balm < 5 < 9 < 30 < 15 < 20
Carver MDA Rudbeckia / Black-Eyed Susan < 5 < 9 < 30 < 15 < 20
Dakota MDA Rudbeckia / Black-Eyed Susan < 5 < 9 < 30 < 15 < 20
Dakota MDA Monarda / Bee Balm < 5 < 9 < 30 < 15 < 20
Dakota MDA Delphinium / Larkspur < 5 < 9 < 30 < 15 < 20
Dakota MDA Leucanthemum / Shasta Daisy < 5 < 9 < 30 < 15 < 20
Hennepin MDA Liatris / Blazing Star < 5 < 9 < 30 < 15 < 20
Hennepin MDA Sedum / Stonecrop < 5 < 9 < 30 < 15 < 20
Hennepin MDA Sedum / Stonecrop < 5 < 9 < 30 < 15 < 20
Hennepin MDA Agastache / Giant Hyssop < 5 < 9 < 30 < 15 < 20
Hennepin MDA Azalea / Azalea < 5 < 9 < 30 < 15 < 20
Rice MDA Monarda / Bee Balm < 5 < 9 < 30 < 15 < 20
Rice MDA Eupatorium / Joe Pye Weed < 5 < 9 < 30 < 15 < 20
Rice MDA Buddleia / Butterfly Bush < 5 < 9 < 30 < 15 < 20
Washington MDA Platycondon / Balloon flower < 5 < 9 < 30 < 15 < 20
Washington MDA Echinacea / Coneflower < 5 < 9 < 30 < 15 < 20
Washington MDA Veronica / Speedwell < 5 < 9 < 30 < 15 < 20
Wright MDA Weigela / Weigela Not analyzed < 9 < 30 < 15 < 20
Page 7
Figure 1. Examples of labeling that was considered pollinator friendly. Plants with labeling such as this
were subject to sampling.
Figu
re 2. Distribution of samples collected during 2015.
Page 8
2016
A total of 55 flower samples were collected between April 6 and August 31, 2016. The samples came
from 20 sales locations statewide. The plants sample d were all labeled or advertised as pollinator-
friendly. Samples were collected from annual and perennial plants, and dependent on what plants
were in bloom and advertised as pollinator friendly at the time of inspection.
Each sample was tested for acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam
adapting a laboratory procedure that yielded a result consistent with the “N o Observed Adverse Effect
Level.” Positive results were found for two of the five chemicals: acetamiprid and imidacloprid.
Imidacloprid was found in six samples from three locations. The levels found ranged from 38.4 parts
per billion (ppb) to 497 ppb (Table 2). Acetamiprid was detected in six samples collected from one
location. Of the 55 samples collected, 21.8% tested over the NOAEL for a systemic insecticide. Of the
20 locations where samples were collected, 15 % had plants advertised as pollinator friendly that
contained systemic insecticides above the NOAEL.
During this season, the capacity of the MDA Lab Services Division to perform these analyses became an
issue. The MDA has responsibility for a high volume of pesticide analysis during the growing season
that required priority over these samples. Samples that were collected very early in the nursery
inspection season were quickly analyzed by the lab; however, when other pesticide testing demands
grew too large, the rest of the plant samples collected from nursery settings were frozen and stored
until they could be analyzed later in the year. This meant that samples which were found to be in
violation of law were not identified until the growing season was over and all plant sales were
completed. Although no action could be taken to correct the violation at this point, a Notice of
Violation was issued to each of the four firms.
Due to the complex nature of flowers as a matrix , the MDA Lab did not report results for acetamiprid in
several samples due to unpredictable co-extracts such as color pigments that interfered with the
analysis.
Table 2. Analytical results for plant samples collected during 2016. Sample exceeding the threshold for
each chemical are shown in bold.
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Blue Earth MDA Petunia / Petunia < 5 < 9 < 30 < 15 < 20
Blue Earth MDA Echinacea / Coneflower < 5 < 9 < 30 < 15 < 20
Blue Earth MDA
Monarda / Bee Balm,
Raspberry Wine'
< 5 < 9 < 30 < 15 < 20
Blue Earth MDA Buddleia / Butterfly Bush < 5 < 9 < 30 < 15 < 20
Blue Earth MDA
Monarda/ Bee Balm, 'Pardon
My Pink'
< 5 < 9 < 30 < 15 < 20
Blue Earth MDA Salvia / Sage < 5 < 9 < 30 38.4 < 20
Crow Wing MDA Gillardia / Blanketflower Not analyzed < 9 < 30 < 15 < 20
Crow Wing MDA Leucanthemum / Shasta Daisy Not analyzed < 9 < 30 < 15 < 20
Crow Wing MDA Giaillardia / Blanket Flower 26.4 < 9 < 30 < 15 < 20
Crow Wing MDA Digitalis / Foxglove 17.6 < 9 < 30 < 15 < 20
Crow Wing MDA Monarda / Bee Balm 6610 < 9 < 30 < 15 < 20
Crow Wing MDA Veronica / Speedwell 661 < 9 < 30 < 15 < 20
Crow Wing MDA Astilbe / Astilbe 305 < 9 < 30 < 15 < 20
Crow Wing MDA Phlox / Phlox 403 < 9 < 30 < 15 < 20
Dakota MDA Torenia / Wishbone flower < 5 < 9 < 30 < 15 < 20 Page 9
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Dakota MDA Fuchsia / Fuchsia < 5 < 9 < 30 < 15 < 20
Dakota MDA Salvia / Sage < 5 < 9 < 30 < 15 < 20
Dakota MDA Coreopsis / Tickseed < 5 < 9 < 30 < 15 < 20
Dakota MDA Geranium / Geranium < 5 < 9 < 30 61.8 < 20
Dakota MDA Begonia / Begonia < 5 < 9 < 30 135 < 20
Dakota MDA Coreopsis / Tickseed < 5 < 9 < 30 497 < 20
Dakota MDA Begonia / Begonia < 5 < 9 < 30 135 < 20
Dakota MDA
Geranium, Petunia,
Thunbergia / Flower combo
mix
< 5 < 9 < 30 61.8 < 20
Hennepin MDA Osteospermum / African Daisy < 5 < 9 < 30 < 15 < 20
Hubbard MDA Kniphofia / Torch Lily < 5 < 9 < 30 < 15 < 20
Hubbard MDA Coreopsis / Tickseed < 5 < 9 < 30 < 15 < 20
Hubbard MDA Hemerocallis / Daylily < 5 < 9 < 30 < 15 < 20
Hubbard MDA Rudbeckia / Black-Eyed Susan < 5 < 9 < 30 < 15 < 20
Hubbard MDA Platycondon / Balloon Flower < 5 < 9 < 30 < 15 < 20
Itasca MDA Petunia / Petunia < 5 < 9 < 30 < 15 < 20
Itasca MDA Coreopsis / Tickseed < 5 < 9 < 30 < 15 < 20
Itasca MDA Echinacea / Coneflower < 5 < 9 < 30 < 15 < 20
Itasca MDA Achillea / Yarrow Not analyzed < 9 < 30 < 15 < 20
Itasca MDA Nepeta / Cat Nipp < 5 < 9 < 30 < 15 < 20
Itasca MDA Heliopsis / Oxeye < 5 < 9 < 30 < 15 < 20
Itasca MDA Liatris / Blazing Star < 5 < 9 < 30 < 15 < 20
McLeod MDA Asclepias / Milkweed Not analyzed < 9 < 30 < 15 < 20
McLeod MDA Agastache / Anise Hyssop < 5 < 9 < 30 < 15 < 20
McLeod MDA Liatris / Blazing Star < 5 < 9 < 30 < 15 < 20
Olmsted MDA Aquilegia / Columbine < 5 < 9 < 30 < 15 < 20
Olmsted MDA Coreopsis / Tickseed < 5 < 9 < 30 < 15 < 20
Olmsted MDA Petunia / Petunia < 5 < 9 < 30 < 15 < 20
Olmsted MDA Buddleja /Butterfly Bush < 5 < 9 < 30 < 15 < 20
Ramsey MDA
Argyranthemum / Marguerite
Daisy
< 5 < 9 < 30 < 15 < 20
Ramsey MDA Pentas / Pentas < 5 < 9 < 30 < 15 < 20
Scott MDA Petunia / Petunia < 5 < 9 < 30 < 15 < 20
Scott MDA Alyssum / Alyssum < 5 < 9 < 30 < 15 < 20
Scott MDA Geranium / Geranium < 5 < 9 < 30 < 15 < 20
Scott MDA Osteospermum / African Daisy < 5 < 9 < 30 < 15 < 20
Scott MDA Petunia / Petunia < 5 < 9 < 30 < 15 < 20
Steele MDA Hemerocallis / Day Lily < 5 < 9 < 30 < 15 < 20
Steele MDA Veronica / Speedwell < 5 < 9 < 30 < 15 < 20
Washington MDA Leucanthemum / Shasta Daisy Not analyzed < 9 < 30 < 15 < 20
Washington MDA Monarda / Bee Balm < 5 < 9 < 30 < 15 < 20
Washington MDA Coreopsis / Tickseed < 5 < 9 < 30 < 15 < 20
Page 10
Figure 2. Distribution of samples collected during 2016.
Page 11
2017
During 2017, 47 samples were collected for analysis. Eleven samples were analyzed by the MDA Lab
Services Division prior to the beginning of their busy season. The rest of the samples collected were
analyzed by Legend Technical Services, Inc. under contract with the MDA. This allowed for a quick
turnaround on sample results throughout the growing season and the ability to require corrective
actions for sites that had violations.
MDA Nursery Program inspectors reported that it was difficult to find enough volume of flowering
plants advertised as pollinator -friendly in 2017. Forty-seven samples were analyzed, down from 55 the
year prior. That difficulty was reflected in the reduced number of entities sampled in 2017. Fourteen
entities were sampled compared to 20 the year prior. At least two entities sampled in 2016 contacted
the MDA during winter 2016-17 to discuss their options. As a result, these entities had no advertising
posted in 2017 which precluded repeat sampling. Other entities removed pollinators from their
advertising and were also not sampled.
Each sample was tested for levels of acetamiprid, clothianidin, dinotefuran, imidacloprid, and
thiamethoxam exceeding the “N o Observed Adverse Effect Level .” During 2017, the EPA released
values for chronic toxicity to honey bees for these chemicals. These values were lower than the values
for acute toxicity that had been previously used. In response, the MDA lowered the thresholds so that
lower concentrations of the chemicals would be reported (Table 3).
Levels exceeding the NOAEL were found in six samples. One sample contained clothianidin ,
imidacloprid, and thiamethoxam. One sample contained clothianidin and imidacloprid. One sample
contained dinotefuran and imidacloprid. Three samples contained imidacloprid alone.
Of the 47 samples collected, 12.7%were positive for at least one of the five neonicotinoid insecticides
included in the analysis. This was a decrease from the 21%in 2016. Twenty-eight percent of the sites
sampled had plants labeled as pollinator friendly but containing systemic insecticides. The positive
samples were obtained from four sites: two independent nurseries and two sites from a large retail
chain. None of these sites has violations in 2016. As a result of the timely results, Notices of Violation
were issued to the three entities (2 locations were for the same retailer) and follow-up inspections
confirmed that pollinator advertising was removed from the remaining inventory.
Table 3. Analytical results for plant samples collected during 2017. Sample exceeding the threshold for
each chemical are shown in bold.
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Anoka Legend Echinacea / Coneflower < 4.0 7.9 < 5.0 66 5.7
Anoka Legend
Ligulistylis / Meadow Blazing
Star
< 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend
Eryngium / Rattlesnake
Master
< 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Lobelia / Cardinal flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Veronia / Ironweed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Tradescantia / Spiderwort < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Phlox / Phlox < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Coreopsis / Tickseed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5 Page 12
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Benton Legend
Penstemon / Smooth
Beardtongue
< 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Carlton Legend Coreopsis / Tickseed < 4.0 < 6.0 < 5.0 69 < 5.5
Carlton Legend Leucanthemum / Shasta
< 4.0 < 6.0 < 5.0 84 < 5.5
Carlton Legend Salvia / Sage < 4.0 < 6.0 < 5.0 41 < 5.5
Carlton Legend Aquilegia / Columbine < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Carver Legend Heliopsis / Oxeye < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Carver Legend Liatris / Blazing Star < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Carver Legend Phlox / Phlox < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Clay Legend
Osteospermum / African
Daisy
< 4.0 6.7 < 5.0 94 < 5.5
Clay Legend Ranunculus / Buttercups < 4.0 < 6.0 20 230 < 5.5
Clay Legend Gerbera / Gerber Daisy < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Dakota Legend Scabiosa / Pincushion < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Goodhue Legend Agastache / Hyssop < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Goodhue Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Kalimeris / Kalimeris < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Eupatroium / Boneset < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Monarda / Bee Balm < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Phlox / Phlox < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Lobelia / Cardinal flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Allium / Flowering Onion < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Heliopsis / Oxeye < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Centaurea / Cornflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Ramsey Legend Pentas / Pentas < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Ramsey Legend Pentas / Pentas < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Ramsey Legend Pentas / Pentas < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Ramsey Legend Salvia / Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Ramsey Legend Tagetes / Marigold < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Ramsey Legend Petunia / Petunia < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Washington Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Winona Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Winona Legend Liatris / Blazing Star < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Winona Legend Senna / Senna < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Winona Legend Zephyranthes / Zephyr lily < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Winona Legend Asclepias / Milkweed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Winona Legend Desmodium / Tick-trefoil < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Page 13
Figure 3. Distribution of samples collected during 2017.
Page 14
2018
During 2018, MDA Nursery Program inspectors submitted 39 flowers samples for analysis to Legends
Technical Services. Retail locations such as box-stores and garden centers were sampled across the
state, with the bulk of the samples coming from the Twin Cities metro area. Thirty-nine samples were
analyzed, down from 47 the year prior. As awareness of the law has grown, fewer sellers are
advertising plants as pollinator friendly and the number of entities where samples could be taken fell
to 10 from 14 the year prior.
Two samples contained levels of insecticides above the NOAEL, with the average turnaround time for
analytical results at 12 days. Notices of Violation were issued to the two entities selling the plants.
These entities used out of state suppliers as well as their own stock and willingly removed the
pollinator advertising.
Each sample was tested for acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam
adapting a laboratory procedure that yielded a result consistent with the NOAEL. Positive results were
found for two of the five chemicals: clothianidin and imidacloprid. Imidacloprid was found in one
sample from one location at 5.1 ppb. Clothianidin was detected in one sample collected from one
location. The level found was 12 ppb. Only 5% of samples were found to be in violation. Twenty
percent of sites with samples collected were in violation.
Table 4. Analytical results for plant samples collected during 2018. Sample exceeding the threshold for
each chemical are shown in bold.
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Anoka Legend Buddleia / Butterfly Bush < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Osteospermum /African Daisy < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Verbena / Common Vervain < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Leucanthemum / Shasta Daisy < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Angelonia / Angelonia < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Gazania / Traling Gazania < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Scabiosa / Pincushion Flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Phlox / Phlox < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend
Penstemon / Smooth
Beardtongues
< 4.0
< 6.0
< 5.0 < 4.5 < 5.5
Benton Legend
Penstemon / Slender
Beardtongues
< 4.0
< 6.0
< 5.0 < 4.5 < 5.5
Benton Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Zinnia / Yellow Zinnia < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Zinnia / Red Zinnia < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Coreopsis / Tickseed < 4.0 < 6.0 < 5.0 5.1 < 5.5
Hennepin Legend Dahlia / Dahlia < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Salvia / Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Pentas / Pentas < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Dahlia / Dahlia < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Heliotropeium / Heliotrope < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Asclepias / Butterfly Weed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Buddleia / Butterfly Bush < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Phlox / Phlox < 4.0 < 6.0 < 5.0 < 4.5 < 5.5 Page 15
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Hennepin Legend Monarda / Bee Balm < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Hemerocallis / Daylily < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Salvia / Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Gillardia / Blanket Flower < 4.0 12.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Monarda / Bee Balm < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Veronica / Speedwell < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Salvia / Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Asclepias / Butterfly Weed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Heliopsis / Oxeye < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Liatris / Blazing Star < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
McLeod Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
McLeod Legend Buddleia / Butterfly Bush < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Figure 4. Distribution of samples collected during 2018.
Page 16
2019
In 2019, MDA Nursery Program inspectors collected 50 flowers samples for analysis by Legends
Technical Services. Retail locations such as box -stores and garden centers were sampled across the
state and in each nursery inspector territory. The bulk of the samples came from the Twin Cities metro
area. Four samples resulted in levels of insecticides above NOAEL, with the average turnaround time
for these positive sample at 14 days.
The number of entities that requested pollinator C ompliance Agreements remained the same at six.
Two types of Compliance Agreements were written this year, o ne for entities intending to advertise
plants as beneficial to pollinators and the other claiming freedom from certain chemicals or systemic
insecticides.
Fifty samples were analyzed, up from 39 the year prior. That was a slight increase reflected in the
increased number of entities sampled in 2018, 14 compared to 10 the year prior.
Each sample was tested for acetamiprid, clothianidin, dinotefuran, imidacloprid, and thiamethoxam
adapting a laboratory procedure that yielded a result consistent with the NOAEL. Positive results were
found for one of the five chemicals: imidacloprid. Imidacloprid was found in fo ur samples from two
locations. The levels found ranged from 6 ppb to 3500 ppb.
Sample analysis will be reviewed for 2020 as well as any potential additions to the list of systemic
insecticides the MDA is analyzing for.
Table 5. Analytical results for plant samples collected during 2019. Sample exceeding the threshold for
each chemical are shown in bold.
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Anoka Legend Veronica / Speedwell < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Anoka Legend Agastache / Hyssop < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Eupatorium / Snakeroot < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Allium / Flowering Onion < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Eutrochium / Joe Pye Weed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Benton Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Carlton Legend Hieracium / Hawkweed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Carlton Legend Salvia / Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Dakota Legend Silphium / Compass Plant < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Dakota Legend Verbena / Vervain < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Dakota Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Dakota Legend Agastache / Hyssop < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Dakota Legend Lobelia / Cardinal Flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Heuchera / Coral Bells < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Salvia / Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Coreopsis / Tickseed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Nepeta / Catnip < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Salvia / Sage < 4.0 < 6.0 < 5.0 3500 < 5.5
Hennepin Legend Gillardia / Blanket Flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Dianthus / Dianthus < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Delphinium / Larkspur < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Aquilegia / Columbine < 4.0 < 6.0 < 5.0 11 < 5.5 Page 17
County
Processing
Lab
Product Sampled
Genus / Common Name
Acetamiprid
ppb
Clothianidin
ppb
Dinotefuran
ppb
Imidacloprid
ppb
Thiamethoxam
ppb
Hennepin Legend Aquilegia / Columbine < 4.0 < 6.0 < 5.0 6 < 5.5
Hennepin Legend Salvia / Sage < 4.0 < 6.0 < 5.0 16 < 5.5
Hennepin Legend Duranta / Duranta < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Canna / Canna Lily < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Leucanthemum / Shasta Daisy < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Hennepin Legend Scaevola / Half flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Sedum / Stonecrop < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Perovskia / Russian Sage < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Itasca Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
McLeod Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
McLeod Legend Coreopsis / Tickseed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
McLeod Legend Lobelia / Cardinal Flower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
McLeod Legend Leucanthemum / Shasta Daisy < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Norman Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Norman Legend Achillea / Yarrow < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Norman Legend Phlox / Phlox < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Olmsted Legend Echinacea / Coneflower < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Olmsted Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Pope Legend Eupatorium / Snakeroot < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Pope Legend Allium / Flowering Onion < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Pope Legend Helenium / Sneezeweed < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Pope Legend Rudbeckia / Black-Eyed Susan < 4.0 < 6.0 < 5.0 < 4.5 < 5.5
Pope Legend
Ratibida / Upright Prairie
Coneflower
< 4.0 < 6.0 < 5.0
< 4.5
< 5.5 Page 18
Figure 4. Distribution of samples collected during 2018.
Page 19
Summary
Table 6 provides a summary of the number of locations sampled and number of samples collected
during each year since this law was passed. As awareness of this law has increased, the percentage of
samples that have been found in violation has decreased. This decrease has occurred even though the
reporting levels for samples in violation has also decreased as information has become available from
the EPA.
Table 7 provides a listing of all samples that have been found in violation and the concentration in
parts per billion (ppb) of the target chemical. The experience of the Minnesota Department of
Agriculture in enforcing this law is that plants that are in violation typically have concentrations well
above the EPA NOAEL for honey bees which would indicate that the current thresholds in place for
reporting are adequate.
Table 6. Summary of locations visited, samples taken, and violations found, 2015-2019.
2015 2016 2017 2018 2019
# samples 19 55 47 39 50
% samples with violations 0% 22% 13% 5% 8%
# locations 7 20 14 10 14
% locations with violations 0% 20% 29% 20% 14%
Table 7. A listing of all samples found to be in violation and the concentra tion of the chemical found
(ppb), 2015-2019.
Chemical 2015 2016 2017 2018 2019
Acetamiprid
17.6
Acetamiprid
26.4
Acetamiprid
305.0
Acetamiprid
403.0
Acetamiprid
661.0
Acetamiprid
6610.0
Clothianidin
6.7 12.0
Clothianidin
7.9
Dinotefuran
20.0
Imidacloprid
38.4 41.0 5.1 6.0
Imidacloprid
61.8 66.0
11.0
Imidacloprid
61.8 69.0
16.0
Imidacloprid
135.0 84.0
3500.0
Imidacloprid
135.0 94.0
Imidacloprid
497.0 230.0
Thiamethoxam
5.7