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Sustainable growing media

This group of projects is focusing on how to define and measure the sustainability of growing media.

We do not want to replace one ‘unsustainable’ material with another and be in the same position again in a few years needing to replace another material. We also need to understand and agree the context in which a material is sustainable in relation to the environmental problems we are trying to solve in moving to sustainable growing media.


  • P1: Defining and agreeing the ‘environmental’ problem we are trying to solve – is focusing on how the context of peat reduction in horticulture has changed since the 1980s and 1990s and how the debate should now be framed. Any changes to the substrates used in horticulture must at least solve our agreed environmental problem and should not create new ones. This is closely linked to project P12 on what the horticultural sector will look like in 2030.
  • P3: Clarifying the greenhouse gas emissions (carbon footprint) associated with different growing media – is examining how to build on scoping work funded by Defra on how to define and measure the carbon footprint of different growing media.
  • P4: What does a sustainable growing medium look like? – is identifying the criteria to use in assessing the sustainability of growing media and assessing the performance of a range of different growing media input materials against thems.
  • P5: Sustainable growing media stewardship principles and certification – this is a longer term project that will not start until after the completion of project P4. If the materials assessed in project P4 are sustainable or are sustainable under certain conditions we need a mechanism for ensuring that that the conditions are met and the materials used continue to meet our sustainability criteria. Do we need our own stewardship scheme for sustainable growing media or can all of the individual materials be dealt with under existing schemes such as the Forest Stewardship Council certification scheme for the wood products and Fairtrade for concerns over labour issues with coir in India and Sri Lanka? The level of third party audit required will depend on how the assessment is to be used, the weight it is to be given and affordability. There is also potential for the proliferation of new assessment schemes and another is being proposed by the Task Force under project P7. Opportunities for bringing together schemes proposed by the Task Force need to be explored

Page last modified: 29 March 2012