Abstract:
The term “sustainable growing media” is widely used in horticultural research, policy, and industry, yet its meaning remains ambiguous, inconsistently applied, and often unsupported by evidence, undermining the very decisions it is meant to guide. Materials are frequently characterised as sustainable based on single attributes, such as being peat-free, recycled, renewable or aligned with policy priorities, without demonstrating reliable horticultural performance, economic viability, social responsibility or reduced environmental impact within real production systems. This paper examines why defining sustainable growing media has proven persistently challenging and why a single, universal definition may be neither achievable nor even useful. Drawing on existing literature and policy initiatives, we analyse sustainability through its environmental, economic and social pillars, highlighting how narrow or assumption-based assessments obscure trade-offs and shift, rather than reduce, environmental and social burdens. We argue that sustainability in growing media is not an inherent material property but a context-dependent outcome that must be demonstrated within a defined production system. Rather than proposing a new definition, we outline eight minimum conditions for responsible use of the term, emphasising measurable impacts, functional performance, economic feasibility, and explicit treatment of trade-offs. Where such evidence is lacking, precise, verifiable descriptors should replace broad sustainability claims.
The article is available via the following link: https://www.frontiersin.org/journals/horticulture/articles/10.3389/fhort.2026.1800902