As those who work in a nursery will appreciate, raising young plants is the horticultural equivalent to a chef spending hours in front of a hot stove to create the perfect dish. A lot of hard work takes place behind the scenes to serve up well-nourished plants that are a feast for the senses.
Fortunately, ICL Specialty Fertilizer’s iconic Levington growing media make this demanding process easier for commercial growers.
Tried and tested recipes
Offering a healthy start for young plants, the Levington Advance range includes two off the shelf brands, Levington Advance and peat-free Levington Advance Sustain. These products have been vigorously trialed and tested to prove the high quality ingredients offer great results. ICL’s technical manager Andrew Wilson says: "These products have been proven to work year after year, our customers trust our products which is why ICL are proud Levington Advance is part of our Grow, Nurture, Protect package."
The Levington Advance Solutions custom mix package allows growers to work with ICL advisors to develop a bespoke growing media program customized to meet the needs of the plants. The ICL Professional Horticulture team are BASIS and FACTS qualified (or studying towards) and also have accumulatively over 100 years’ experience working within the horticultural industry. Levington Advance Solutions allow growers to have their own growing media mix made at ICL’s state of the art growing media facility which incorporating Osmocote controlled release fertilizers, and plant protection products, such as Exemptor for vine weevil control.
Wilson explains: "Levington Advanced Solutions offers our customers the best nutrition program suited to the plant’s needs. We have great relationships with our growers which allows us to fully understand their plants they grow and by using our Angela Web 2.0. software we are able to recommend the bespoke packages to match individual growers’ requirements."
Getting the balance right: the science behind the Levington range
A winning growing media custom mix that produces quality plants must meet many criteria, including the ability to hold the optimum amount of water, air and nutrients for the plants. In fact, the relationship between air and water is one of the most important considerations when selecting the best peat mix for your crop, notes Andrew. "Getting the right grade and quality of peat with the perfect balance of water and air is essential, for instance a very fine peat will hold plenty of water but will contain virtually no air, limiting the growth of the plant. Conversely larger particles can lead to high air filled porosity but very low water holding, so a balance is crucial. "
He explains that air-filled porosity (AFP) – the proportion of peat’s volume that is filled with air – is the recommended way of measuring this air-water relationship. "If you are growing a long-term crop outside and experience high rainfall, you will have a high AFP [such as 20 to 25 per cent]. But if you are growing plug plants in small cells you would require a lower AFP [around 10 per cent] as you wouldn’t want them to dry out too much."
With this in mind, ICL blends peat into different grades by particle sizes – from 0-3mm (which has a lower AFP) up to 10-25mm (which has a higher AFP). Combining medium aged Scottish peat with younger, white, Irish peat in ICL’s state-of-the-art Nutberry factory located on the Scottish border, ICL are able to produce a high quality peat grades to get the balance just right for different growing situations. Andrew says: "We mix the peat very carefully, making the most out of that valuable resource."
Lime is also added to the mix to adjust the pH and provide magnesium and calcium along with a base fertilizer, Start & Gro, providing further nourishment to the Levington Advance range. Andrew explains: "It gives the plant the best start providing everything it needs, including trace elements such as molybdenum, copper, boron, zinc, iron and manganese. It’s about the getting the right nutrition at the right time. Andrew adds "Micromax Premium is a trace element booster package that lasts up to 18 months and is now available in all Levington Advance standard growing media.
Another key ingredient is H2Gro, which is a blend of surfactants that acts as both a wetting and a re-wetting agent (for long-term cycles). Andrew explains: "Water on its own can bead up on the surface or take the vertical path of least resistance leaving dry patches in the growing media which may cause nutrients being unavailable. H2Gro breaks down the surface tension allowing instant vertical and lateral movement of water making up to 100% of nutrients in the growing media available to the plant."
Levington Advance standard growing media includes:
- Levington Advance Seed & Modular. Mixed for seed sowing and/or direct rooting of cuttings, this product features a low or a medium base level of fertilizer to meet the individual requirements of these delicate, young crops.
- Levington Advance Bloom. This product has been formulated for the bedding and pot plant market, and contains the controlled release fertilizer, Osmocote Bloom.
- Levington Advance Pot & Bedding. With particles no larger than 10mm, this part of the range is ideal for a 12mm pack up to 9cm pots.
- Levington Advance Potting. Also featuring low base fertilizer levels, these growing media products are designed to provide a good, open, well-drained structure.
- Levington Advance Container Nursery Stock (CNS). This includes three specialist mixes – namely Levington Advance CNS General, which is made up of a blend of 0-10mm and 6-12mm peat to allow the mix to flow easily into smaller pots yet retain an open structure for drainage, Levington Advance Ericaceous, which has less lime to allow for a lower (more acidic pH) and Levington Advance CNS Coarse is made up of a blend of 0-10, 6-12 and 10-25 mm particles of peat. It is a more open mix suitable for larger pots and overwintering stock outdoors.
Increasing confidence in peat-free growing
Sustainably-sourced, peat-free substrates such as (ICL’s) Fibagro (created from woodchips that are heated and shredded), coir (made from the pith of coconut husk), and bark (usually sourced from pine trees) are added to custom-made mixes. In fact, Wilson says that many growers are using 40 per cent peat-reduced compost these days. These peat-free substrates are also the key ingredients in Levington Advance Sustain (peat free), which comes in several different peat-free mixes, including:
- Seed & Modular,
- Pot & Bedding,
- Pot Plant, and
- Container Nursery Stock
Whilst many commercial growers are successfully using peat-reduced and peat-free mixes, Andrew admits that peat is still the industry’s preferred growing media. The reasons for this are many – including the varying availability and cost of these alternatives. Usefully, a five-year AHDB Horticulture Project (CP 138) named "Transition to responsibly sourced growing media use within UK Horticulture" is aiming to boost the industry’s confidence in "peat-free" as it strives to reach Government’s target of (the year) 2030 for the voluntary phasing out of peat. This multi-partner project finishes next year (2019) and is part-funded by the UK’s leading growing media manufacturers, including ICL Professional Horticulture.
One of the project’s key aims is to construct a science-based model for cost-effective, desirable, peat-free blends. Chloe Whiteside, horticulture consultant (protected crops) for research station ADAS – which is leading the project – says: "This project will help ‘short-circuit’ the trials process for both growing media manufacturers and growers when it comes to using a new material, or blend, in horticulture. The other benefit of our approach is that if the raw materials change between the previous years’ testing and subsequent manufacture then the ratio of materials can be adjusted at the actual point of mixing at the factory. Growers can then use the ‘designed product’ in commercial crop production."
A key observation so far has been that peat-free growing media can require slightly different watering and feeding (irrigation and nutrition) regimes. But, says Chloe, "if that can be managed well, and a grower can learn how to treat them differently, then peat-free growing media products produce marketable quality plants." For example, last year’s (2017) trials during weeks 21 and 25 at Merseyside-based Ivan Ambrose nursery on pansy and petunia in polystyrene double six-packs found that all three blends used in the experiment produced marketable crops. Chloe noted that one blend in particular was very similar to the nursery control in terms of pack cover and plant size.
Andrew agrees that the trials will enable the horticulture industry to learn more about the components of peat growing media. In the meantime, ICL’s Levington Advance range continues to offer growers a varied and sustainable choice for growers. Wilson concludes: "If you buy a Levington Advance product you can be assured that it’s got high quality raw materials and its designed to do the job.
- This is content produced in partnership with ICL