Are you getting the most from your peat-free?

Levington Advance Sustain peat-free professional growing media has gained significant market share in the UK ornamentals sector.  Launched in 2015, it has been embraced by propagators, bedding producers, perennial and container nursery stock (CNS) growers as well as tree producers looking to transition away from peat.

Sustainable growing media is heavily reliant on wood-based products and there is potentially greater risk of plant quality suffering from poor nutrition. A double whammy of growing media materials having a lower nutrient buffering capacity, combined with greater propensity to lock up N.

Overcoming these specific challenges, ICL has simultaneously researched and developed novel nutrition and wetting agents, helping growers transition away from peat – with minimal adjustments to their crop management practices.

What is nutrient match release technology?

Delivering super-efficient and effective nutrient release, Osmocote 5 controlled release fertilisers (CRF) feature unique nutrient matching release technology and an improved Optimised Trace Element Availability (OTEA) system. Matching plants’ nutrition needs throughout the release programme – Osmocote 5 delivers improved plant colour, health and growth.

The S-shaped nutrient release curve starts slowly and increases as the plant’s demand rises; while a slightly higher N content improves overall growth – as sustainable media mixes tend to have lower nutrient buffering capacity.

Although required in relatively small quantities, trace elements play a vital role in biochemical metabolic processes. Highly reactive elements, such as Iron and Copper, can often become unavailable to the plant. The Osmocote 5 OTEA system super enhances trace element release, with iron boosted by up to 300%. Fully EDTA chelated, each element remains soluble, with availability improved at higher pHs, often associated with sustainable mixes.

What role can advanced wetting agents play?

ICL’s advanced wetting agent, H2Gro, contains a unique blend of surfactants to aid water management. With a 3 in 1 mode of action, it improves wetting and spreading, penetration and rewetting.  Routinely incorporated into Levington Advance peat-reduced mixes, a double rate is used in Levington Advance Sustain mixes to improve water management.

Have you seen our ‘Peat-free in action’ results?

In 2024, ICL conducted extensive peat-free nutrition trials in CNS. Those who attended our Hort Science Live ‘Peat-Free in Action’ event last July had the opportunity to see the results at first hand.

While of course N is very important, water-soluble nutrition added at the start – such as calcium nitrate – can be quickly leached. Our trials clearly showed the benefit of adding controlled forms of N; such as ICL’s Osmoform High N, a slow-release N for shorter-term crops such as perennials; and our fully coated Osmocote N (5-6 month) for longer terms CNS. The results showed controlled N leads to greener plants with more shoots and flowers, whereas water soluble N initially gives rise to faster soft growth, but is followed by higher leaching and inferior, paler coloured growth.

When it comes to core nutrition, typically higher rates of Osmocote are required to produce top quality plants – this is also true with peat free. Choosing the right longevity can help too. In our increasingly cool summers, an 8-9month Osmocote 5 delivers 25% enhanced release, compared to the same rate of 12-14month Osmocote 5. The same effect as increasing the rate of the 12-14month Osmocote 5 by 1kg.

What peat-free trials are planned for 2025?

With UK FSC sustainable woodfibre set to have a greater part to play in peat-free mixes in the future, ICL’s 2025 peat-free trials will explore blends of different Fibagro Advance grades to create mixes with the optimum water air properties. This will involve blending up to four grades of woodfibre, in much the same way as peat grades were blended in the past. The results are very encouraging when combined with a well-balanced nutrition package – including Osmocote N, Osmocote 5 and Micromax Premium trace elements, plus our H2Gro wetting and water management agent.

Did you know?

Our highly experienced team and skilled technical field team works with customers to tailor management practices to our Levington sustainable substrates. Employing our Angelaweb 3.0 precision nutrition programme, they can advise you on nutrition packages tailored to individual situations, taking your nursery’s water quality and growing media into account.

Want to know more?

To set up a meeting, or simply find out more, click here to find the contact details for your local ICL Technical Area Sales Manager.