British Researchers Evaluating New Media Blends to Reduce Coir Reliance

British Researchers Evaluating New Media Blends to Reduce Coir Reliance

New Growing Media BlendsResearch in the United Kingdom has shown that coir-free growing media has the potential to work as well as coir for strawberry crops if irrigation and nutrition are optimized, and these research results likely apply to greenhouse production, as well.

As part of a project to develop responsibly sourced growing media blends as alternatives to peat, a model is being developed to predict the performance of any given blend of growing media for containerized production. Extensive trials to validate the model’s predictions will hopefully ensure that growers can have confidence in their growing media’s commercial performance.


While strawberry growers have already replaced peat with coir to a large extent, there is still concern about the industry’s reliance on a single raw material, so coir-reduced and coir-free blends are being tested as part of the research.

Growers were invited to view the strawberry trials at New Farm Produce in Lichfield, UK, at an event facilitated by the project team and promoted by AHDB Horticulture (a research organization) in April.

“Currently we rely totally on coir, and while it is a good product, it does have limitations,” says Stephen McGuffie of New Farm Produce. “Structure is the most important element of the trial for me over the longer term of two to three years. Both coir-free and coir-reduced media show some promising results as we look at the plant growth; however, we will be more informed on performance when we have the harvest results for this season.”

“We have been using irrigation and nutrition regimes designed for standard coir media,” says Barry Mulholland of ADAS UK, who is leading the research. “Despite this, the trials show coir-free and coir-reduced media have the potential to perform as well as or better than coir, with improved understanding of blend performance and appropriate adjustments to irrigation and nutrition.”

As event attendees learned, there was no significant difference in total yield for bare-root strawberry plants in the coir-reduced or coir-free product blends. There was a slight reduction in yield in the trial blends compared with the coir control sample; however, the research team at ADAS believe that with optimized irrigation and nutrition, there is the potential for coir-free products to work just as well as coir.

The latest annual grower summary from the project will soon be available at