As the longest established large commercial nursery business in Europe, Johnsons of Whixley needs little introduction. Celebrating its centenary in 2021, it has five production sites across N Yorkshire - totalling 120 acres - and produces over 3 million quality shrubs and perennials annually in 2-10 litre pots. What you may not know, is that the company has been 40% peat reduced for over 20 years.

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As Johnsons of Whixley’s Ian Nelson explains: “During the 90’s, like most nurseries of the time, we were 100% reliant on peat based growing media mixes – using different peat fractions to create the bespoke mixes we wanted.

“Then, twenty years ago we took the decision to switch to a 40% peat reduced mix. There were two main drivers - environmental awareness of the need to reduce reliance on peat and production considerations - primarily to create a more free-draining media.

“In nursery stock production, too much water can be more dangerous than too little,” he says. “As borehole water users, our water costs were minimal and over-watering was more of a concern. Keen not to suffer the consequences of over-watering, we adopted a peat-reduced approach which made perfect sense for our business. However, it was key these new mixes worked within our performance parameters and remained highly consistent.”

Consistency is key

“Growing media consistency is vital, whether 100% peat, peat-reduced or even peat-free,” says Ian. “Once you’ve fine-tuned the management of your crop, you need to be confident the next batch of growing media is going to have the same physical characteristics and properties and is going to perform the same way.”

Over these past two decades the nursery has worked with several growing media suppliers. The production team has relied on Levington’s – working with Scotts and now ICL – for many of these years and the current contract is with ICL using its Levington Advance growing media brand.

Peat-free experience

“In recent years we’ve conducted several trials of peat-free products, including Levington Advance Sustain,” says Ian.

“It can be challenging to monitor and assess trials grown within a large commercial crop. However, our Lavender crops are now grown exclusively in Levington Advance Sustain so we have plenty of direct practical experience.

“These crops are definitely benefiting from having a more free-draining media.”

Benefits of Fibagro Advance

Johnsons of Whixley’s peat-reduced and peat-free mixes contain ICL’s Fibagro Advance woodfibre. Manufactured in the UK from home grown FSC sourced wood, it is highly consistent.

“Fibagro Advance has a good environmental profile and is produced using a unique process developed at our Nutberry growing media manufacturing site,” explains ICL’s Martin Donnelly. “With a lower carbon footprint compared to imported woodfibre, it has been rigorously trialled and shown to significantly improve consistency and performance of peat-reduced and peat-free growing media.”

“As a key component of our mixes, it’s reassuring that Fibagro Advance production is under the auspices of ICL – that they have complete control over the production process,” says Ian.

Overcoming challenges

Wood based products tend to be less hydrophilic – water loving – compared to peat. To improve water management, Johnsons of Whixley rely on H2Gro to reduce water usage and therefore wastage.

Woodfibre and bark can also impact on nutrition in peat-reduced and peat-free media.

“Nutrition is affected in two ways, the lock up of nitrogen by microbial activity and the increased leaching due to the lower cation exchange capacity (CEC),” explains ICL’s Andrew Wilson. “Potentially this means more has to be applied”.

“Reduced peat medias commonly have Calcium Nitrate applied as a supplementary Nitrogen source. However, it is highly soluble and the nitrate Nitrogen component is easily leached from the pot. To help overcome these challenges, we have developed new products such as our slow-release Nitrogen - Osmoform High N. This gives more even and long-lasting nitrogen release, significantly reducing nitrate leaching.”

The future

“It’s good to have experience of peat-free media under our belts,” says Johnsons of Whixley’s Production Manager Rob Richardson. “As things currently stand, there isn’t a strong commercial incentive for us to switch any more production to peat-free. We’re just not seeing sufficient demand from the landscaping industry for peat-free plants – this demand hasn’t really changed over the past 20 years.

“Should the legislation regarding peat usage in UK horticulture change, or customer demand for peat-free plants increase, we feel well prepared - it wouldn’t be a major sea change for us.”

He goes on to say: “As an industry as a whole, I think there are some concerns regarding peat substitute availability and consistency. To be viable, peat dilutants need to be available 365 days of the year and to be of a consistent quality.

“If the whole industry needed to switch to peat-free overnight – would there be sufficient peat alternatives available and of the right grade? Such a move is also likely to come with some of its own environmental challenges.”

Technical Area Sales Managers (Turf & Landscape)