When it comes to leafy greens, there’s more to success than nutrient formulas and climate control. Few understand this better than Denis Laci, founder of Agranom and one of Europe’s most trusted crop consultants. With years of hands-on experience and a no-nonsense approach to hydroponics, Denis has helped transform underperforming farms into high-efficiency operations across multiple continents. In this exclusive feature, Denis shares his hard-earned lessons on genetics, airflow, humidity deficit, and why blind faith in off-the-shelf systems can cost growers more than they bargained for. Whether you're just starting your indoor farming journey or optimizing a large-scale greenhouse, his insights offer a powerful reminder: the right setup starts with the right questions.
We need to understand that leafy greens remain a small and relatively immature market. Too often, hydroponic cultivation of lettuce and herbs is compared to high-wire crops in terms of climate control, lighting, irrigation, and other standardized strategies many of which are not yet defined or fully explored in the context of leafy greens.
As a consultant, one of the most critical aspects I emphasize is that every facility is unique. Different technologies, systems, and equipment lead to varied outcomes, and these results cannot simply be replicated from one facility to another.
Among the most common challenges I observe are related to water management, filtration and disinfection, and genetic selection. For example, many growers underestimate the importance of using proper water treatment solutions such as dissolved oxygen systems, UV disinfection, or H₂O₂ treatments. These are well-established methods, but success comes down to selecting the right suppliers and designing a tailored set-up for each facility.
I strongly believe that genetics account for more than 60% of the final success. That’s why I always advise growers to conduct ongoing, small-scale trials with at least three different cultivars throughout the year. This allows for more proactive and timely decision-making when it comes to selecting the best seasonal varieties.
Finally, understanding the full value of semi-closed greenhouses technology, proper screening, pre-day and pre-night strategies, humidity deficit (HD) buildup, air movement, and choosing the right plant density at each cultivation stage are all key success factors that significantly impact results.
When it comes to indoor farms, humidity-defined (H.D.) buildup is one of the most critical parameters to control in order to maintain product quality. One of the simplest ways to manage this is by ensuring proper airflow speed but, in many of the farms I’ve visited, airflow is a limiting factor.
Beyond speed, the direction of airflow is equally important. Relying solely on horizontal air movement is not sufficient. Vertical airflow must also be incorporated to create circular movement around the plant canopy. This promotes higher transpiration rates, which are directly linked to healthier growth and improved product quality.
In terms of climate strategy, maintaining an H.D. value between 1.5 and 3.5 is a safe and effective range. This not only helps to prevent tip burn but also boosts transpiration, leading to higher photosynthesis rates and overall better growth performance.
Another key design factor connected to H.D. buildup is the distance between artificial lighting and the crop canopy. By selecting the right spacing and light intensity, you can address several challenges including optimal radiation levels, effective H.D. control, and maintaining sufficient airflow capacity between the growing tables or lines.
Lastly, material choices within the hydroponic system play a vital role. For example, using gutters that don’t bend (which helps prevent irrigation inconsistencies), and selecting rafts or floats made from the right materials for leafy greens cultivation, are essential considerations to avoid performance issues.
Choosing technologies or setups with a few proven success stories may seem like the easy path to return on investment (ROI), but it goes much deeper than that. For newcomers, avoiding crops like romaine, iceberg lettuce, spinach, and certain herb varieties which are generally more complex to grow is a smart business decision that can improve the chances of achieving a stable and predictable ROI.
When it comes to NFT hydroponic systems, the market has evolved significantly over the past decade. We've seen a transition from closed gutter systems to open gutter designs, and in the last three years, a shift back toward closed gutter setups. This shift reflects the fact that water flow, oxygen levels, nutrient management, and irrigation control are generally more efficient and consistent in closed gutter systems with plugs, compared to open gutter systems where the entire channel is filled with substrate.
Understanding what works long term is essential for achieving better ROI performance.
Technology is a powerful tool, but when the goal is financial return, the driving forces behind new investments should be proven experience and solid industry references not just innovation for its own sake.
There is a significant difference between a trial setup and a commercial facility when it comes to overall performance and product quality. From my experience, every step of the cultivation process from seeding to transplanting, spacing, and harvesting is handled and perceived differently in these two cases.
This gap is a major reason why many facilities around the world struggle to maintain operational efficiency, consistency, and product quality, especially when they rely solely on advice from product suppliers or take the risk of installing new technologies without solid success story references.
At Agranom, education and research are both core values. However, given the complexity of today's commercial facilities with so many varying parameters and technologies involved, it's critical to approach knowledge transfer from research to real-world operations with care. Misapplied information can lead to poor results if not tailored to the unique context of each facility.
I believe that great steps forward have been made on this one, especially with the recent semi-closed greenhouse technology which is proven itself to be much more efficient in terms of water use, CO₂, climate management in extreme outdoor environments and pest control management. With this technology you can say that we almost have an indoor farm which also takes advantage of solar light.
It’s no secret that more and more system suppliers are exploring hybrid hydroponic CEA cultivation models. This approach involves propagating plants in a fully controlled indoor environment using only artificial lighting and then transplanting them into a greenhouse-based hydroponic system to complete the remaining two-thirds of the cultivation using natural sunlight.
The main advantage of starting indoors is the ability to produce strong, healthy young plants while using minimal surface area, thereby improving the space efficiency (m² usage) of the facility.
I’m a strong believer of this system particularly in urban areas such as rooftops, where space optimization is critical. I look forward to seeing how this approach performs in real-world commercial applications.
I’m a strong believer in building relationships and working collaboratively combining strengths to achieve better results that move the industry forward.
Agranom specializes in horticultural lettuce and herb projects, offering a unique blend of hands-on expertise and strategic guidance. From early concept development to daily operations, our mission is to help projects meet the highest industry standards by implementing the right expertise and technologies, with a strong focus on product quality and long-term ROI.
Partnering with Agritecture enhances our ability to deliver even greater value. Agritecture’s international reach, robust planning frameworks, and deep understanding of urban agriculture and CEA make it a natural fit with Agranom’s crop-specific expertise and data-driven approach. Together, we provide a 360-degree consulting solution that bridges the gap between vision and execution, whether that means designing an optimized leafy greens facility, troubleshooting performance issues, or developing a scalable business model.
This collaboration is more than a business relationship; it’s a shared commitment to elevating the CEA industry through education, innovation, and results-driven support.
The transition to sustainable, high-tech agriculture is no longer a luxury, it’s a necessity. In northern climates, CEA is already becoming the standard, driven by harsh outdoor conditions, high labor costs, and increased access to funding.
Meanwhile, southern countries are quickly catching up. Greece recently announced €600 million in funding for new high-tech greenhouse projects starting in 2025. Spain is rapidly shifting from open-field to CEA cultivation, and Mexico is now developing high-tech lettuce and high-wire crop facilities developments that seemed unlikely just a few years ago.
Looking forward, the industry shows tremendous potential. It's encouraging to see more growers and investors prioritizing education/ research and recognizing the value of working with consultants before making major investment decisions. This shift toward informed planning and collaboration sets a strong foundation for the future.
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