Bee friendly plants? Or a deadly trap?

Spring feels like a new start to life. The emerging sun shines on the fresh green leaves and flowers. Buzzing bees and chirping birds enchant the air and warm the heart. Many people visit nurseries and garden centres to buy new ‘Bee Friendly’ plants for their garden or balcony. But they might be in for a very nasty surprise, for a poisoned truth lurks in the shadows. A new Swedish scientific publication shows that many of these plants contain pesticides that are very harmful to bees. And at the same time, a Dutch nature photographer discovered that 9 out of 10 insects fed on the plants she bought simply died.

Our member, The Swedish Society for Nature Conservation SSNC, bought 54 plants marketed as ‘bee-friendly’. They had them analysed for pesticides in flowers, leaves, roots and soil. A disturbing total of 64 different pesticides were found in the plants, many of them banned in the EU. They are either harmful to bees, cancerogenic and/or toxic to aquatic organisms. Nine different pesticides were PFAS.

In terms of percentages: 

  • 54% of the plants contained at least one pesticide toxic to bees
  • 57% of the plants contained at least one pesticide not authorised for use in the EU
  • 76% of the plants contained at least one pesticide classified as CMR
  • 48% of the plants contained at least one PFAS-pesticide
  • 98% of the plants contained at least one pesticide classified as toxic to aquatic organisms

The butterfly bush from Denmark was one of the most contaminated plants. It contained 20 different substances, including Pendimetalin, Prochloraz, Spirodiclofen, the PFAS Tau-Fluvalinate and the bee killer neonicotinoid Thiacloprid. A lavender plant from the Netherlands contained a smaller number of substances but Folpet in levels as high as 137 mg/kg (!) on the flowers. The lavender also contained the PFAS Floncamid on the flowers. An MPS certified lavender with unknown origin contained 22 pesticide residues including the PFAS Flupyradifuron and the non-authorized Indoxacarb (banned in 2022). The unauthorised pesticide residues were found on plants from all countries. 

The plants were bought in Sweden but were grown in Sweden, Denmark and the Netherlands. Surprisingly, they still get a “Made in Sweden” marking even if only the last stage of growth has been in Sweden. So the origin of the plant is not clear to the buyer.

What we have learned from the work on this report is that flowers on retail in Sweden could have been cultivated in several countries before they are sold in Sweden and still get a “Made in Sweden” marking even though only the last growth has been in Sweden. So, to truly know the origin of the plant is difficult since the information about the plants movement across borders is not publicly available. 

The SNCC confronted the growers. 

The study was published in Environmental Pollution and on the scientific website Science Direct. (1)

Earlier tests in the Netherlands

The discussion about poison on plants has been going on for a couple of years in the Netherlands - an important exporter of ornamental plants. Stimulated by PAN Netherlands a popular TV program "Inspection Services of Value" broadcasted alarming results about 'Bee Friendly Plants' in a 2021 sending: 11 out of 14 plants tested had bee-toxic pesticides, 6 out of 14 contained neonicotinoids.

Discussions with the garden centre organisation have been going on for years, but progress is slow. PAN Netherland did another limited test last year on lavender, campanula, buddleia (butterfly bushes), salvia and dahlia. Residue from plant protection products banned in the Netherlands were found on 3 of the 15 garden plants examined. A total of 36 different plant protection products and metabolites of plant protection products were found in the 15 samples. Residue of the insecticides fipronil and fipronil sulphone was found on butterfly bushes grown in Belgium. The plants were sold at Intratuin and Welkoop. PAN Netherlands informed both chains about this and requested them to remove all butterfly bushes of this origin. Subsequent research by the garden centres showed that the Belgian grower in question had not used any fipronil-containing products. However, the insecticide was found in the drain water that the grower used four times during the cultivation of the butterfly bushes. Furthermore, traces of the fungicide propiconazole were detected in dahlias sold at Groenrijk. These plants were grown in the Netherlands. The source of this is still unclear and is being investigated further, but based on this finding PAN Netherlands requested Groenrijk to remove all dahlias of the grower in question from its shelves.

Alarming discovery by Dutch photographer

In her photo project, Dutch Marlonneke Willemsen planned to picture the different stages of growth of insects and snails. She bought conventional garden plants and to her disbelief, 9 out of 10 animals simply died. So she repeated the project. She called it the “Invisible threat: The effect on Insects.”

Shocked by the results of her first photo project Marlonneke decided to repeat the test. She bought all sorts of plants in different garden centres. For each plant she bought, she placed insects that are associated with the plant. She used a control group with the same insects and plants grown without pesticides. With the conventional plants bought in garden centres again 9 out of 10 insects died. The group fed on organic plants thrived and none died.

She presented her findings via two parallel photos of each host plant and its insect. On one you see a nice-looking house plant. On the next, a dead insect. For example, she illustrated the case of the Butterfly Bush (Buddleia) and the Small White butterfly. The plant can be found in countless gardens all over Europe. In the right photo, you see a dead butterfly.

Another case is lavender. Bees and butterflies love it. In the left photo, you can see a lavender plant which can be found on many balconies and gardens all over Europe. In the right photo, you see a dead house cricket with its legs in the air. The same happened with a pot of dahlias and a greenhouse slug. Once it was placed on the plant, it died. 

The photographer saw the same thing happening to almost all the insects and small animals she took pictures of. She is convinced that pesticides are to blame. The Dahlia and Lavender were tested by PAN Netherlands and indeed they contained a cocktail of pesticides. Through her photo project, Marlonneke wants to bring awareness to this worrying issue. Visit her website (2) or better contact her to organise an exhibition or article if you’re interested.

Marlonneke's exhibition and story attracted attention in the Netherlands. She featured in the "What stops us" programme and was quoted in several articles. Her photos were exhibited at RotterdamPhoto, an international photo festival that is part of Rotterdam Art Week. She would like to have more EU-wide visibility, as plants from the Netherlands are exported all over the world. Plants are nice, but without pesticides, please!

Buy organic plants

Conclusion: don’t buy conventional garden plants if you love bees, butterflies, ladybirds and other insects. Look for organic plants grown without pesticides. Hard to find? Here is some good news. On March 5th the Dutch Organic Plant Growers Association was launched. Here is a list of organic growers in the Netherlands (3). Hope you can find organic plant growers in your area too. 

The EU guideline that allows to kill of most insects

Most policymakers do not yet take insects seriously. There is attention at national and at EU level with a pollinators initiative, but this has not yet led to the necessary action to stop the biodiversity crisis. In conventional agriculture, most insects still don’t have a chance, ‘thanks’ to completely outdated guidelines used by the regulators. The EFAS (European Food and Safety Authority) is still using very industry-friendly guidelines to assess the effect of pesticides on insects. See our blog: The EU guideline that allows to kill most insects (4).



Do do you have useful information about research on pesticide use on ornamental plants in your country? Don't hesitate to contact us on communications [at]



  1. Pesticide residues in ornamental plants marketed as bee friendly: Levels in flowers, leaves, roots and soil
  2. Photo project by Marlonneke Willems: “Invisible threat: The effect on Insects” full project
  3. Biologische siertelers in Nederland
  4. Blog: The EU guideline that allows to kill of most insects

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Pesticide Action Network Europe (PAN Europe) gratefully acknowledges the financial support from the European Union, European Commission, DG Environment, LIFE programme. Sole responsibility for this publication lies with the authors and the funders are not responsible for any use that may be made of the information contained herein.