Why the RSS Matters

For decades, peat has been a staple ingredient in growing media due to its excellent water retention and plant growth properties. However, peat forms over millennia in waterlogged bogs and fens, making it essentially a non-renewable resource on human timescales. Harvesting peat for horticulture comes at a steep environmental cost. Peatlands are the UK’s largest carbon store, locking away vast amounts of carbon in their soils. When peat bogs are drained and extracted, the stored carbon is released as carbon dioxide, contributing significantly to climate change. Peat extraction also degrades unique ecosystems, destroying habitats for rare wildlife and undermining natural services like flood control and water filtration. Only about 13% of UK peatlands remain in a near-natural state today, due in part to decades of peat extraction for gardening. These realities have led to a broad consensus that peat is not a sustainable growing media ingredient. Phasing out peat is a crucial step in reducing horticulture’s environmental footprint and preserving our “wild carbon reserves” for future generations.

This is where the Responsible Sourcing Scheme (RSS) for growing media comes in. The RSS was established to help the horticulture industry and consumers navigate these complexities and make informed, sustainable choices. It provides a robust framework for evaluating and comparing the environmental impact of raw materials used in growing media. Instead of focusing on a single issue, the scheme looks holistically at seven key criteria that cover the spectrum of sustainability concerns. Each major ingredient (making up more than 5% of a product) is assessed against these seven criteria:

• Energy Use: How much energy (and what type) is used to extract, process, and transport the material. Using high levels of fossil energy will score lower than using renewable or efficient energy sources.

• Water Use: The amount of water needed in production and any impacts on local water resources. Materials that require excessive water or affect local water availability score lower.

• Pollution: The pollutants and greenhouse gases released during production and transport. This includes carbon emissions contributing to climate change, as well as any air, soil, or water pollution.

• Habitat & Biodiversity: The impact on ecosystems where the material is sourced. For instance, does harvesting the material harm wildlife or degrade natural habitats?

• Renewability: How quickly the resource can regenerate. A material like peat that takes centuries to form is scored very low, whereas something like coir or compost that renews within a year can score the maximum in this category.

• Resource Use Efficiency: How well the process uses the resource and manages waste. This looks at whether parts of the raw material are wasted and if by-products are put to good use.

• Social Compliance: The social and ethical aspects of sourcing, including fair labour practices, community impacts, and whether the supply chain operates safely and transparently. Materials sourced in ways that support worker rights and local communities score higher.

By scoring ingredients across all seven of these dimensions, the RSS creates an overall picture of a growing media product’s responsibility index. Manufacturers and growers can use this information to formulate products that are more sustainable, improving areas that score poorly. For example, if a producer finds that the energy use score of their product is low, they might switch to using renewable energy in production or source materials from closer locations to reduce transport emissions. Likewise, a low social compliance score might prompt a switch to suppliers with better fair-trade or worker safety standards.

Crucially, the Responsible Sourcing Scheme isn’t run by a single interest group, it’s a collaborative, industry-wide effort. The scheme was developed by the Growing Media Association (which represents growing media manufacturers) in partnership with major retailers, the UK government’s Department for Environment, Food & Rural Affairs (Defra), and leading environmental NGOs. Growers, manufacturers, retailers, NGOs, and Defra have all had input to ensure the scheme is balanced and effective. This broad collaboration means the RSS reflects a consensus on what responsible sourcing should look like, and it has credibility from all sides of the horticultural community. The scheme’s governance includes independent auditing of the data and claims, so that the scores and ratings are trusted and verified.

The role of the RSS is ultimately to promote continuous improvement and transparency. By providing a clear framework and common language for sustainability, it helps the industry identify where improvements are needed and track progress over time. It also helps gardeners and commercial growers alike make informed choices. Products that comply with the scheme can display a rating on packaging and at point of sale, so that consumers can easily compare how responsible different products are. In this way, the scheme empowers consumers to support sustainable practices, and rewards manufacturers who invest in better sourcing.

Responsible sourcing matters because it underpins the future of sustainable horticulture. By moving away from peat and rigorously assessing alternatives, the industry can ensure that our pursuit of greener gardens does not come at the expense of wetlands in England, forests in Europe, or water supplies in Asia. The Responsible Sourcing Scheme provides the tools and guidance to make this possible. It embodies the principle that improving sustainability is a shared responsibility, from the peat bog and the coconut plantation, all the way to the bag of growing media in your shed. By choosing products that carry the RSS standard, gardeners and professionals are joining a collective effort to protect ecosystems, reduce carbon emissions, use resources wisely, and support fair supply chains. Together, these choices drive the market toward growing media that is not only good for plants, but also good for the planet and people who help those plants grow.

Phasing out peat is a necessary step toward sustainability, but it doesn’t automatically guarantee a low-impact alternative. Every substitute material used in growing media has its own environmental footprint. Whether derived from plant waste, forestry by-products, agricultural residues, or recycled organics, each comes with a unique set of strengths and challenges.

For example, some materials may be highly renewable but require large amounts of water or energy to process. Others might be locally sourced and reduce transport emissions, but have limited supply or variable quality. Certain by-products help to reduce waste and improve circularity, but may carry inconsistencies in performance or contamination risks if not well managed.

The environmental and social impact of any material depends on how it is produced, transported, and processed, as well as how it performs in the final product. That’s why simply replacing peat isn’t enough, we must also evaluate the full life cycle of each alternative and make sure it truly represents a more sustainable choice.

The Responsible Sourcing Scheme recognises this complexity. It was designed to ensure that all raw materials are assessed on a level playing field, using clearly defined, independently verified sustainability criteria. This way, both manufacturers and consumers can understand not just what is in the bag, but how responsibly it was sourced.