When should a commercial grower consider switching to a tailored substrate?

A commercial grower should consider switching to a tailored substrate when a standard growing medium is visibly limiting crop performance, reducing resource efficiency, or no longer matching the demands of a specific crop, cultivation system, or local climate. The trigger is rarely a single event; it is usually a pattern of underperformance that a generic off-the-shelf product cannot resolve.

What are the signs that a standard substrate is limiting crop performance?

The clearest signs are persistent pH instability, poor root zone aeration, inconsistent water distribution, and nutrient uptake problems that cannot be corrected through irrigation or fertilisation adjustments alone. When these issues recur across consecutive crop cycles, the substrate itself is usually the root cause.

Substrate pH is one of the most reliable early indicators. For most greenhouse crops, the optimal range sits between roughly 5.4 and 6.2. Outside this window, micronutrient availability drops sharply and plants show deficiency symptoms even when fertiliser inputs appear adequate. If runoff EC is consistently more than 0.5 mS/cm higher than the irrigation solution EC, salt accumulation is occurring — a signal that the growing medium is no longer functioning as intended.

Physical structure matters equally. Fine particles increase water retention but reduce air porosity, restricting root development. Coarse particles support drainage, but an unbalanced particle size distribution creates uneven irrigation patterns. A substrate that loses its ability to re-wet reliably makes irrigation management unpredictable.

How does a tailored substrate differ from an off-the-shelf growing medium?

A tailored substrate is formulated around the specific requirements of a defined crop, cultivation system, and local growing conditions. Water retention, air ratio, pH buffering, starter nutrient charge, and particle structure are all calibrated to a grower’s exact situation rather than averaged across many potential users.

Standard substrates provide a reliable baseline and suit growers whose requirements fall within the typical range. However, as growers develop more refined crop management methods, a generic product increasingly becomes a constraint. Tray size, irrigation system type, local water quality, climate, and the vegetative or generative balance required for a specific variety all influence what the ideal substrate should look like — and no single off-the-shelf product can optimise all of these variables simultaneously.

At Kekkilä-BVB, both the BVB Substrates and Kekkilä Professional brands follow a tailored development approach, working with academic partners including Wageningen University and Research to validate new substrate compositions before commercial use.

Which crops benefit most from a crop-specific substrate?

Crops with narrow tolerance ranges for pH, moisture, aeration, or pathogen exposure benefit most — in practice, soft fruits, ornamental plants, medicinal cannabis, mushrooms, young plants, and leafy greens grown in automated systems.

Strawberries, raspberries, and blueberries are sensitive to root diseases caused by Fusarium, Pythium, and Phytophthora, which thrive in low-aeration substrates. Each strawberry growing method demands a different substrate composition, making a single generic product unsuitable. For ornamental pot plants, BVB Substrates developed BVB Compact to keep plants compact without chemical growth regulators — important for growers holding an MPS sustainability certificate. For medicinal cannabis, the substrate must perform differently at the seedling stage (high aeration, fast root development) than during flowering (stable pH, controlled moisture).

Young plant production requires consistent air content, water distribution, and starter nutrient levels across every cell of every tray. For leafy greens in automated gutter systems, substrate structure must integrate reliably with mechanical handling infrastructure, and food safety testing adds a further quality dimension that generic products may not address.

When does switching substrates make financial sense?

Switching makes financial sense when the total cost of production under the current growing medium exceeds what a better-matched substrate would deliver — accounting for labour, resource consumption, crop losses, and supply reliability, not yield alone. Trial evidence from BVB Substrates showed yield improvements of 5–7% in cucumber and tomato crops when a substrate innovation was introduced. Trials with professional pepper growers in the Netherlands showed equal or higher yields alongside no crop losses due to wilt disease across any trial location.

Supply security is a growing concern across the European market. Growers who have transitioned to certified tailored alternatives are better positioned when raw material availability tightens. A substrate formulated from a secure and diversified raw material base reduces the risk of mid-season substitutions that disrupt crop consistency. Precise matching of water and nutrient requirements also reduces input waste and the cost of over-irrigation or corrective fertilisation.

What should a grower evaluate before making the switch?

Before switching, a grower should evaluate five areas: water quality, irrigation system compatibility, substrate certification, key performance indicators, and supplier consistency. Water quality is the starting point — carbonate hardness determines how substrate pH will shift during cultivation, and growers should submit water samples to a laboratory before finalising any specification.

Irrigation system compatibility is often underestimated. A change in substrate structure affects how water moves through the root zone, meaning dripper specifications and pressure settings may need adjustment. RHP-certified substrates are independently verified for water uptake, air content, pH, EC, nutrient levels, and freedom from contaminants. Finally, growers should define KPIs — covering plant growth rate, labour, input consumption, and crop losses — before the trial begins, to enable an objective evaluation.

How do you work with a supplier to develop a tailored mix?

The process begins with a detailed assessment of water retention requirements, vegetative or generative balance, air ratio, cultivation system design, and sustainability requirements. At Kekkilä-BVB, sales advisors with direct horticultural backgrounds translate these requirements into a substrate specification, drawing on data from research partners including Wageningen University and Research and Proefcentrum Hoogstraten.

Growers are active participants throughout. Dutch young plant producer Gipmans worked with Kekkilä-BVB over several years to develop BVB Grandio, a blocking substrate combining performance with a higher share of circular raw materials — a process that was iterative, evidence-based, and rooted in real growing conditions. New raw materials undergo multiple validation rounds before entering a commercial mix; reed canary grass reached commercial use only after four years of R&D and successful grower trials.

For growers ready to begin, the practical first step is to bring a substrate analysis and an irrigation water report to the initial discussion. The more precisely a grower can describe their substrate performance criteria, the more targeted the resulting tailored solution will be.