Project 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 them.

Project description

There are two stages to this, firstly to identify the sustainability criteria to be used (originally excluding carbon and greenhouse gas emissions which were being covered by project P3 and which would be fed into this project at a later date) and secondly to assess different growing media ingredients against these criteria.

The growing media ingredients to be assessed are neither an exhaustive list nor an approved list of ingredients identified by the Task Force. The list is also not static and we would expect other materials in future to be tested against the same set of criteria. However, the baseline consideration for materials assessed is that they are capable of delivering the required performance as an ingredient in growing media (and, therefore, this project should be viewed in combination with project P7). It should be noted that the majority of the materials being assessed are not used singly but in combination with each other. This will affect the sustainability of products made by combining different ingredients.

Project Lead: Paul Alexander (RHS)

P4a: Sustainability criteria

What are the sustainability criteria that all materials should be judged against? 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. What are the sustainability opportunities and threats going forward? What is the potential supply of different materials and the competition threat from other industries?

Project Lead: Paul Alexander (RHS)

Dependencies: P1 – we need to be clear on the environmental problem being addressed so that the criteria can determine if alternatives solve the original problem/s and/or do they create their own new problems.

Deadline: Meeting on 12 January 2012 to determine sustainability criteria and a key set of questions against which all of the current growing media ingredients (including peat) should be assessed.

This project then splits into a number of work streams assessing each ingredient - P4b-4j: Assessment of materials

Progress/Update

At the inception meeting, in January 2012, representatives from growers, manufacturers, retailers and NGO’s, discussed the idea of where we as an industry would like to be in 30 years. Do we (horticulture), want to be reliant upon imported products and materials or would we prefer to be more self reliant, perhaps even sustainable? Consensus was that we’d prefer to be more self reliant.

Stewardship schemes (e.g. FSC) that promote sustainable production / management are usually based on a “promise”. This promise essentially offers a description of the product to the user offering clarification regarding its sustainability. The stewardship scheme qualifies the promise by identifying criteria that are deemed important for that promise and then identifies measurable elements for each criteria allowing differentiation between products. The measurable element reflecting what it is the scheme is trying to avoid or encourage.

The initial project discussion focused on where the group thought we should start and stop defining the sustainability of the materials / products. We agreed that we should try to apply “sustainability” to the mixed material effectively at end of production belt (including additives like fertilisers and water retaining gels) but not including packaging or any onward transport / use / disposal. It was felt by the group that any promise regarding sustainability regarding a product should account for everything in the bag. The group then defined a promise that they felt reflected an aspiration of what they’d like to be able to say;

“All growing media are made from raw materials that are environmentally and socially responsibly sourced and manufactured.”

A number of environmental and social criteria were then listed to for use in qualifying this promise.

A subsequent project meeting in February 2012, attended by the sub-project leaders responsible for the assessment of different feedstock materials, began by agreeing that while the language (including the promise) has to be absolutely correct for the finished version of the project, we needed to accept a degree of flexibility for now in order to make progress. The meeting then discussed the proposed criteria and developed a short-list for initial use.

The short-list of criteria includes:

• Availability
• Renewability
• ‘Reduce, reuse, recycle’
• Location of raw material (or “resource security”)
• Water use in production
• Energy use in production
• Ecosystem services and habitat
• Ethical issues

This was then populated with measurable variables that attempted to capture what it was we were trying to avoid or encourage about each criteria, i.e. the best to worst case scenario. In general a five point scale was adopted but in some cases only the extremes were defined to allow the sub-project leaders flexibility in their interpretation. The sub-project leaders are currently evaluating the criteria with examples from their material and will reconvene (in late April) to discuss what worked and what didn’t work.

Although the focus so far had been on bulk raw material inputs the 1 March 2012 Task Force meeting confirmed the need for this group to also account for fertilisers and other additives as well as proposing the inclusion of a measure for carbon / greenhouse gas balance as project P3 would not be able to deliver this.