A new peat-free pasteurised coir growing media - developed by ICL (formerly Everris) working with Sheepgate Nursery in Lincolnshire, is being used to supply a major watercress transplants contract with Vitacress.

“The UK vegetable propagation industry primarily relies on peat based growing media,” says Bruce Grant, MD of Richard Grant & Son (Leverton) Ltd.  “Transplant producers experimented with up to 20% coir dilutions, but it proved more difficult to manage.  With no pressure from customers to reduce our peat usage, and little relevant industry research supporting its use, we largely turned our back on peat-reduced options, until now.” 

“Growing vegetable transplants in tiny cells, typically just 15ml, is a challenge,” explains ICL technical area sales manger John Clarke. “The growing media must be extremely fine and consistent for mechanical tray filling.  The media must be very finely graded and the nutrient and pH must be consistent.” 

The UK’s leading propagator of watercress, Sheepgate supply up to 5.75 million plants a week in the peak season.  The tiny cells, just 5cc in size, are multi seeded producing 15-25 plants per cell.   

“Our client insisted on a sustainable, environmentally friendly alternative to peat based growing media,” says Bruce. He turned to ICL, his existing growing media supplier, for help. 

Working with John Clarke and his colleague David Bellmont, operations manager at ICL’s growing media production facility, a novel pasteurised coir growing media has been developed.   The coir is supplied by Cocogreen – a company fully accredited in the quality, environmental and social aspects of its business. 

“The coir is ground and milled to size and then steam pasteurised to guarantee freedom from vegetative pathogens including E. coli, Listeria and Salmonella, this is an added bonus for our customers,” explains David Bellmont.  “We start with consistent high quality coir which is milled to a fine size and then steamed to a certain temperature for a set period of time. Our pasteurising process guarantees the coir is free from vegetative pathogens.  It is not possible to steam pasteurise peat as it turns to sludge.” 

“Coir has different physical properties to peat which alter its water and nutrient management,” says Bruce.  “The challenge has been to produce high quality plants within the same time scale.” 

Sheepgate Nursery Manager Kevin Pinner was tasked with mastering watercress production in the pasteurised coir – a challenge he has overcome.  Kevin has applied this new expertise to produce a range of brassica transplants in coir with impressive results. 

“Major retailers are constantly looking at ways of becoming, and being seen to be, more environmentally friendly,” says Bruce.  “At Sheepgate we can offer a range of vegetable transplants grown peat free in a product from a sustainable source which is also guaranteed pathogen free.”