Staying within the walls of your own greenhouse rarely broadens your perspective. That's why cultivation advisors regularly visit growers and connect digitally to exchange ideas and share knowledge. But when the opportunity arises to gather fresh insights quickly and efficiently—through presentations, discussions, and on-site company visits—all in just two days, it's one not to miss. Cultivators, a company that also provides cultivation consulting, gave growers exactly that opportunity on 16 and 17 June, during the Leafy Hydroponics Summit.
A handful of Dutch growers—and even more international ones—seized the opportunity with both hands. A group of suppliers also joined on the first day to share their expertise and continued the next day with site visits across the region. Participants had the chance to take a closer look behind the scenes at Plantenkwekerij Gitzels, Green Simplicity, Enza Zaden, and JASA Packaging Solutions—each offering a unique perspective on innovation in leafy hydroponics.
William Gitzels explains about the plant nursery he runs with his son Mike. View the full photo report here.
New greenhouse with lettuce on water
On Tuesday morning, plant propagators Mike and William Gitzels guided the group through their steadily expanding nursery, which has grown significantly in recent years through ongoing new construction. Enza Zaden has also invested in new facilities. Participants had the chance to visit their new lettuce breeding greenhouse, where crops are grown on movable gullies.
This spring marked the first trial runs on the new system from Industrial Product Solutions. Previously, lettuce varieties were grown and evaluated on a static setup. By switching to movable gully systems, the setup now better reflects real-world growing conditions, especially for growers working with NFT (Nutrient Film Technique) systems.
It's also more convenient for the breeders. The gullies can be gradually moved forward based on crop growth stages, making monitoring and evaluation more efficient. And when a breeder like Mark Koppies needs to step between the rows, the gullies simply slide aside at the push of a button, as he demonstrated to a group of colleagues on Tuesday morning.
Mark Koppies, breeder at Enza Zaden, in the new greenhouse with lettuce on NFT gutters. View the full photo report here.
Growing at high density
In addition to visiting the new NFT greenhouse, the program also included a tour of Enza Zaden's high-density cultivation greenhouse. Here, they grow lettuce at a density of 600 plants per square meter, aiming to stay closely aligned with commercial practices.
"Depending on the crop, region, and variety, growers typically choose a planting density between 250 and 1,000 plants per square meter," explained Jean-Baptiste Malblanc.
The greenhouse combines HPS and LED lighting and features a mist system that activates every few minutes. This setup allows Enza Zaden to replicate a wide range of climatic conditions from around the world, ideal for simulating real-life growing environments. With this facility, Enza Zaden collaborates closely with retailers, growers, and supply chain partners to drive innovation in hydroponic lettuce production.
The lettuce from high-density cultivation could also be closely examined and felt. View the full photo report here.
In North America, the first major growth wave in hydroponic lettuce production began several years ago. And in Europe, where climate challenges and stricter crop protection regulations are making open-field lettuce cultivation increasingly difficult, a similar shift is expected. Exactly when the market will fully transition remains to be seen, but one thing is clear: that turning point is getting closer. Many in the industry believe that ongoing climate-related pressures, which affect the availability of lettuce during certain parts of the year, will only accelerate the move toward controlled environment hydroponics.
A look behind the scenes at JASA, with Ruurd Schut speaking. View the full photo report here.
Packaging
JASA Packaging Solutions is also betting on the growth of indoor lettuce cultivation. The company provides machines and complete packaging and weighing solutions for the CEA market—the well-known abbreviation for Controlled Environment Agriculture.
Earlier that morning at Enza Zaden, the conversation focused on maximizing shelf life for lettuce and leafy greens. While genetics play a key role, packaging is just as critical. That's where JASA steps in: helping both growers and retailers package lettuce as effectively as possible.
Unlike a few years ago, JASA now focuses increasingly on offering a single modular machine platform that can handle various packaging applications. Additionally, the company emphasizes its role as a system integrator, offering tailor-made solutions that fit seamlessly into growers' and packers' operations.
Eduard de Haan, JASA's CCO, shared the company's ambitious vision and strategy during his presentation. Now operating out of a spacious new facility in Obdam, the company aims to double its production capacity between 2023 and 2027 to better serve the growing CEA market.
JASA's expanding global footprint—with locations in the USA, Canada, Germany, and, since 2024, the Middle East is helping drive this growth. The company is also broadening its reach beyond the fresh produce sector, for example, by supplying packaging solutions for raw chicken products to a major Dutch client—an expansion that supports its wider ambitions.
View the photo report from day 2 of the Leafy Hydroponics Summit full of tours.