The HTA has received the below communication from Defra detailing businesses responsibilities on GM material in ornamental plants. This follows the news from earlier in the year that orange petunias in the UK supply chain have been found to be genetically modified, click here for the list of species affect.



1.           The purpose of this note is to:

  • raise awareness of the risk that seeds and plants may contain or consist of unauthorised genetically modified (GM) material; and
  • help the ornamental plant sector to address this risk.


2.           Earlier this year it was found that producers of petunias across the EU were unwittingly marketing GM plants.  Although this did not pose a safety risk it is illegal to sell GM plants for which, as here, no statutory authorisation had been granted.  Therefore action had to be taken to stop marketing of the affected petunia varieties.  Along with one UK breeder, this incident affected importers and retailers of petunias in the UK, putting them to some inconvenience and cost.


3.           It is not known exactly how GM plants originally entered the petunia supply chain.  The inference is that some years ago an experimental GM plant line was cross-bred with conventional plants, and that through further crossing the number of affected varieties increased over time.  The incident highlighted that the ornamental plant sector is not immune from the risk of adventitious GM presence, and that it should seek to manage that risk as far as is reasonably possible.   


Having suitable controls in place


4.           Companies trading in ornamental plants and seeds are legally responsible for ensuring that they do not market unauthorised GM material[1].  Moreover, given the potential consequences to their business, it will be in their own interests to take steps to counter this possibility.  As the ornamental sector is characterised by diverse production chains and associated propagation techniques, there is no ‘one-size-fits-all’ prescription for the controls that should be applied.  However, it may be helpful to set out in general terms what importers or producers of plants and  seeds can do to minimise the potential for a problem to arise. 


Production controls


5.           These may include the following elements:

  1. Provenance of production materials – documentation detailing the source of the seed or plant material, including the breeder and country of origin, and confirmation that the material has been produced from non-GM lines
  2. Variety maintenance – evidence that the variety has been maintained in isolation from other lines  
  3. Growing season controls – documentation detailing the controls in place to prevent possible cross-contamination from GM plants 
  4. Controls during processing, storage and transport – confirming suitable measures have been taken to prevent GM cross-contamination at this stage


6.           If written statements (“letters of assurance”) are requested from suppliers as a proxy for direct control or knowledge of production controls, they should refer to the specific controls that have been applied to the seed or plant material in question. 


Analytical testing


7.           Various techniques may be used to test whether seed or plant material is GM but the most common method is known as PCR - polymerase chain reaction.  Using PCR it is possible to test for a range of genetic elements that are commonly used in the creation of GM organisms.   


8.           Testing of seeds or plant material should:

  1. Be carried out on a representative sample of material
  2. Include appropriate positive and negative controls
  3. Address the potential of false-positive results (e.g. by including controls that preclude positive results due to environmental contamination)
  4. Be conducted to a high level of sensitivity (e.g. to detect a GM presence of at least 0.1% in seed)
  5. Provide a clear indication of any standards or accreditation to which the analysis conforms (e.g. ISO17025, UKAS, etc.)
  6. Report the actual test result and the associated confidence limit (e.g. ±95%)


9.           Testing should not be the only approach that is taken to guard against unwanted GM presence.  Indeed, on its own it may give a false sense of security.  Where testing is pursued our advice is that it should be combined with production controls as outlined at paragraph 5 above.   


10.         If companies suspect or have confirmed that they are holding unauthorised GM seeds or plants they should report this immediately to the relevant regulatory authority[2].


Genetic Resources and GM Team

Department for Environment, Food and Rural Affairs

September 2017

[1] In England the sale of unauthorised GMOs is prohibited by Part VI of the Environmental Protection Act 1990 (, as read with the Genetically Modified Organisms (Deliberate Release) Regulations 2002 ( There is an equivalent legal position in Wales, Scotland and Northern Ireland. 

[2] The relevant authorities are:


HTA GM Petunia Notice for Garden centres

Customers may ask questions about GM (genetic modification) material in orange-flowered petunias. This follows reports in the press, referring to Finland and other EU member states.


Here are some facts for staff to help handle any queries:

The orange-coloured petunias pose no threat to people, animals or the environment;

The petunias are not frost-hardy and neither the plants or their seeds will survive in a British winter;

The orange-flowered GM petunias cannot spread into the wild in the UK countryside;

No other UK bedding or ornamental plants have been found to contain GM material, and special EU authorisation is required for any such developments;

GM petunias are not authorised for cultivation in the EU;

There is EU authorisation for some blue-flowered cut flower carnations but they are not authorised for cultivation in the EU.

Should the customer require more detailed information about GM and the law, please refer them to Defra: 0345 933 55 77, or

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