How is professional growing media tested and validated before commercial use?

Professional growing media is tested and validated through a multi-stage process covering raw material inspection, laboratory analysis, controlled growing trials, and independent certification before any product reaches commercial use. The process confirms that a substrate performs consistently across physical, chemical, and biological parameters under real cultivation conditions.

What tests are performed on professional growing media?

Professional growing media testing covers three distinct categories: physical properties, chemical properties, and phytosanitary safety. Raw materials are assessed for purity, colour, and smell, then subjected to laboratory analysis covering pH, electrical conductivity (EC), moisture content, bulk density, and structural stability. Only materials that pass every stage enter production.

Physical testing focuses on how a substrate manages the relationship between water and air, including water retention, absorption rate, air volume, and structural stability over time. European standard EN 13041 covers physical property determination, including dry bulk density and total pore space.

Chemical testing centres on EC and pH as primary indicators, alongside macro and trace element composition and heavy metal content. The substrate research process at Kekkilä-BVB assesses all three chemical property categories as part of every new formulation evaluation. Phytosanitary testing confirms the absence of weed spores, harmful micro-organisms, and plant pathogens, and verifies that no germination inhibition occurs in the medium.

How do laboratory results translate into crop performance?

Laboratory results provide a reliable baseline for predicting how a growing medium will behave, but they are not a direct guarantee of crop performance. Actual results depend on how substrate properties interact with irrigation management, climate conditions, and plant genetics in a real cultivation environment.

pH and EC values are the most operationally significant lab outputs for growers. pH governs micronutrient availability, and even small deviations from the target range can affect plant development. A substrate that looks correct on paper may still require adjustment once placed under real growing conditions.

To bridge the gap between laboratory data and practical outcomes, Kekkilä-BVB operates six laboratories alongside dedicated trial greenhouses known as phytotrons. Products are also tested in collaboration with independent research institutions, including Wageningen University and Research, and through practical trials with customers at commercial growing sites.

What role do crop trials play in growing media validation?

Crop trials confirm whether a substrate performs as predicted when plants are actually grown in it under real management conditions. No amount of laboratory analysis can fully replicate the complexity of a live crop cycle, making field and greenhouse trials a non-negotiable validation stage.

Trials typically measure biomass, root development, germination rate, and the mineral composition of plant tissue and drainage water. Kekkilä-BVB’s validation model advances new formulations to customer trials only after intensive laboratory and phytotron testing has been completed. The company’s fit-for-purpose substrate development approach combines different raw materials to optimise effectiveness and resource efficiency before commercial release. The RHP certification scheme also uses grow tests to verify that no weeds, pests, or pathogenic organisms are present, with certified products subject to random sampling throughout the supply chain.

How long does the validation process take?

The full validation timeline typically spans at least one to two years from initial raw material screening to commercial release, and can extend considerably longer for novel or complex formulations. RHP certification alone takes approximately one year from quality manual implementation to certificate award.

The raw material screening phase eliminates many candidates early. Kekkilä-BVB has tested over a dozen new raw materials through its innovation programme, and most did not meet performance criteria before reaching the trial stage. For novel peat-alternative materials, timelines are particularly extended. Research published in Frontiers in Horticulture in 2025 noted that replacing peat remains a deeply complex challenge due to raw material variability and the absence of reliable standards for most alternative materials.

What industry standards and certifications apply?

Professional growing media is governed by voluntary certification schemes, European regulatory requirements, and standardised test methods. The most widely recognised voluntary standard is the RHP quality mark, which covers the entire production chain from raw material extraction through to delivery.

RHP certification requires substrates to meet defined thresholds for water uptake, air content, pH, EC, and nutrients, and to be free from heavy metals, weed seeds, and pathogens. As of 2025, more than 70 companies hold RHP certification. EU Regulation 2019/1009, the Fertilising Products Regulation, brought growing media under a harmonised European framework from July 2022, introducing contaminant limits and requiring documented laboratory testing, with CE marking as the outcome. CEN analytical standards including EN 13037 for pH and EN 13038 for EC underpin both regulatory compliance and certification audits. Kekkilä Professional’s production also operates under ISO 9001 and ISO 14001 certification.

How is growing media validation different for specialty crops?

Specialty crop validation requires substrate testing to be tailored to the specific growth stages, root architecture, and environmental sensitivities of each crop type. For medical cannabis, substrate selection has a direct effect on vegetative growth, rooting success, and flower yield. BVB Substrates has developed stage-specific growing media for medical cannabis, with distinct formulations for propagation and flowering.

Forest nursery production presents different requirements, with formulations needing to meet precise specifications for screening grade, starter fertiliser composition, and wetting agent performance across extended growing periods. Mushroom cultivation is addressed through a dedicated RHP certification category with particular focus on casing soil quality. For every specialty application, the core principle remains the same: substrate properties must be confirmed to support the specific biological requirements of the crop at every stage of its development.

This content was generated with the help of AI and it may contain mistakes