Friends of the Earth supporters have petitioned 10 of the biggest garden centre groups after research by Professor Dave Goulson showed 70% of the plants tested from a number of stores contained neonicotinoids.
Wyevale Garden Centres told Friends of the Earth, after 18,000 Friends of the Earth supporters signed an online petition, "we will be working harder to seek the… removal of the three European banned neonics from the complete supply chain during 2018."
Homebase said they "don't use the neonicotinoids" in question: "We continue to be guided by Defra and comply with EU legislation regarding the use and sale of pesticides. As the science surrounding bee populations matures, we will continue to be vigilant and remain committed to taking responsible action with regards to ranges, working closely with our suppliers and partners."
Friends of the Earth bee campaigner Nick Rau said: "We’re aware there are supply chain issues to resolve, such as plug plants originating from Israel, Colombia, Kenya or wherever, and this will take time to sort out."
He added that some garden centres he spoke to are looking at following B&Q’s lead and eliminating all neonics, though not ready to go public yet. He says he has also had feedback that integrated pest management alternatives have proved both cheaper and more effective than neonicotinoids.
Rau said: "We’re delighted that leading garden retailers are responding to public concern and mounting scientific evidence by saying ‘no’ to plants grown with bee-harming chemicals.
"We’re particularly pleased the UK’s biggest garden centre Wyevale has listened to the thousands of people who contacted them and has pledged to work harder to ensure the removal of restricted neonicotinoids from its supply chain.
"We now urge Homebase to follow suit and reject these chemicals too.
"People up and down the country have been creating pollinator-friendly gardens – they need to be confident that the plants they buy are not going to harm Britain’s bees.
"The UK government must also act on neonicotinoids by backing a full and permanent EU ban on these chemicals across Europe – and pledging to keep any restrictions post-Brexit."
Goulson said: "There is currently lots of interest in making our gardens into havens for bees and other wildlife, which is fantastic. Hence we were very sad to discover that most of the pretty flowers marketed as 'bee-friendly' by garden centres, and bought by well-meaning people with their hard-earned cash, actually contain significant concentrations of highly potent insecticides.
"It is great to see many garden centres responding positively to our research by moving to ban neonicotinoids. Hopefully we can soon reach a point where 'bee-friendly' plants are completely free of insecticides."
An EU-wide moratorium, which came into force in December 2013, restricts the use of three neonicotinoids - imidacloprid, clothianidin and thiamethoxam - on crops attractive to bees.
Among other retailers Friends of the Earth contacted, which did not include any supermarkets, online or TV retailers, or large garden centres with fewer than 10 sites, Dobbies said: "We are working with our supply chain to ensure we offer products that are free of these neonicotinoids in the future."
Klondyke said: "The Klondyke Group are working with suppliers to manage the issue with Neonicotinoid Pesticides. All of our current supply base for flowering plants do not use any of the three currently banned Neonicotinoid pesticides. Any new suppliers will be checked for the use of Neonicotinoid pesticides before they are taken on as a supplier."
Blue Diamond said: "We do not use any of the banned (suspended / restricted) neonicotinoids. We will continue to monitor our suppliers and supply chain and endeavour to ensure our plants are not grown using harmful neonicotinoids."
Notcutts said: "Notcutts Garden Centres does not want any of the garden plants it sells to be grown with any use of the three neonicotinoid pesticides clothianidin, imidacloprid, or thiamethoxam and will require all of our suppliers not to use these chemicals on the products they supply to us."
Squire's said: "Three neonicotinoid pesticides - clothiandin, imidacloprid and thiametoxam - have been restricted in use by the European Union. These active ingredients may be harmful to bee populations. It is Squire’s aim not to sell plants that have been treated with these ingredients. We are in regular contact with our suppliers to ensure this is upheld."
Hillier said: "The three EU restricted Neonicotinoids are not used by Hillier, or by any of our supply chain. Hillier Nurseries have further ceased to use any chemicals containing any Neonicotinoids in the production of wholesale ornamental crops. We have identified the companies in our supply chain who continue to use Neonicotinoids currently and we are working with them to only offer Neonicotinoid free products in the future."
Hillview said: "We have the same position as the other retailers in that we are working with our current plant suppliers to ensure that the plants we sell are only beneficial to the environment and wildlife. We will look to ensure that they, and any future growers, more than fulfill any best practice expectations.
"We don't want any of the plants we sell to be grown with the three neonicotinoid pesticides clothianidin, imidacloprid, or thiamethoxam. We are working closely with our suppliers to ensure we offer plants that are free of these neonicotinoids now and in the future. Currently we are not aware of any plants being subject to these pesticides and we continue to monitor the current and prospective growers."
NFU acting chief science and regulatory advisor Chris Hartfield said: "The NFU has always said policy decisions – such as restricting the use of neonicotinoids – must be based on sound science and good evidence and we will continue to make that case. It is still the case that there is no clear evidence neonicotinoids are causing widespread declines in bee populations.
"Friends of the Earth base their approach on recent research, but fail to mention that the same research could not show whether the net effect of planting ‘pollinator-friendly’ flowers contaminated with pesticides was positive or negative for bees – basically the research couldn’t conclude whether or not traces of pesticides on flowering plants is a bad thing for bees. To help pollinators we ought to take action that we know will help, rather than action where we know we can’t measure any benefits."