Peat-Free Growing Media Trials for 2026

Peat-Free Growing Media challenges in Ireland

With the New Year, my focus turns to the upcoming growing season and the planning of ICL’s trial programme.

Ireland & UK’s ornamental horticulture is undergoing significant change, mirroring wider shifts in the global economy, and this is clearly reflected in our trial priorities. My aim is to stay ahead of the curve by developing and validating technical solutions that address the challenges growers are likely to face in the coming years. This means supporting the continued transition to sustainable, peat-free growing media and the adoption of biodegradable fertiliser coatings.

A reliable supply of consistent, high-quality peat-free raw materials is essential as demand continues to increase year on year. In 2025, coir supplies from India and Sri Lanka were disrupted by conflict and adverse weather conditions, resulting in higher costs and variable quality due to elevated salt levels. While pine bark remains the preferred bark material for professional horticulture, its availability can also be constrained.

ICL trial site

Woodfibre Growing Media to reduce Coir reliance

To reduce reliance on imported coir, ICL has invested significantly in the research, development, and production of Fibagro Advance woodfibre. Manufactured from a by-product of local FSC-certified timber production, Fibagro Advance is now available in four grades, ranging from superfine to coarse. My trials focus on optimising air-filled porosity and water-holding capacity by blending two or more grades, allowing coir levels to be reduced while improving water management and overall plant quality. Following successful nursery trials in 2025, these mixes are now being adopted by key growers in 2026, with further advanced trials continuing this year.

Managing Nitrogen lock-up in Peat-Free substrates

Managing nitrogen availability remains a critical challenge when using bark and woodfibre in substrates. In response, we carried out extensive nutrition trials in 2025 using our latest nitrogen solutions – controlled-release Osmocote N (5–6 month) and slow-release Osmoform High N.

These trials identified effective application rates that maintain nitrogen availability throughout the crop cycle without the nutrient leaching commonly associated with traditional calcium nitrate use.

In addition, last year we completed successful trials with Osmocote CalBoost (2–3 month) 20-5-5+2CaO+7MgO, a unique calcium booster specifically designed for peat-free growing media, and scheduled for launch in 2026.

We also rigorously tested Biodegradable N Boost (5–6 month), the first product in our future biodegradable fertiliser range. I’m now planning further trials throughout 2026.

Biodegradable Fertiliser trials for future Osmocote

As part of ICL’s preparations for its next generation, biodegradable Osmocote range, extensive trial programmes are underway in the UK and Ireland and across Europe. These are helping to fine-tune product performance ahead of its planned release in 2028, aligned with forthcoming EU legislative changes, which the UK and Ireland are expected to follow.

In summer 2025, ICL took a leading position by securing approval for the world’s first biodegradable coated nitrogen fertiliser Eqo, on which Biodegradable N Boost is based. In 2026 this work will continue at our trial stations worldwide. Here in the UK, we are commissioning an independent trial at the NIAB crop science organisation in Cambridge, alongside the launch of our first UK/Ireland-based grower trials.

Grower trials and Hort Science Live events

Conducting trials on working nurseries is a vital step in ensuring real-world relevance. To facilitate this, I work closely with Brendan Howell and our experienced team of UK Technical Area Sales Managers to identify suitable trial sites and provide practical support. Together, we set out to showcase these trial results at industry events throughout the year, particularly through our Hort Science Live events and Masterclasses.

10 Years of Hort Science Live Innovation

In 2026, we are proud to celebrate 10 years of Hort Science. The programme will reflect this milestone with a strong focus on innovation, practical advice, and solutions designed to help the industry meet future challenges with confidence.