Large-scale hydro leek cultivation launched in Ypres, Belgium

A 3,000 m² production basin that yields as many leeks annually as 1.5 to 2 hectares in an open field? What until recently seemed like a vision of the future has now become reality. On the Boudry family farm in Ypres this spring, the first large-scale open-air cultivation of hydro leeks was launched. With this, Inagro, REO, Hydromasters, and Indurra, supported by Vlaio and co-financed by the European Union, are taking a step towards more efficient leek cultivation while addressing the climate and environmental challenges facing the sector.

Hydro leeks do not grow in soil, but on carriers floating in a production basin with continuously circulating nutrient water. "In this cultivation system, we control water and nutrients down to the last detail, optimising growing conditions and thus producing uniform, healthy leeks in a shorter cultivation period," says Tim De Cuypere, researcher at Inagro. "This allows us to efficiently achieve multiple growing cycles per year. In addition, the high plant density ensures optimal production."

The closed water system also prevents the leaching of fertilisers and reduces the use of plant protection products. Weeds have no opportunity to grow, and soil-borne diseases are eliminated.

From test set-up to field production
The first steps were taken in 2015, followed by nearly a decade of intensive research and development. After successful trials in smaller basins, the concept was implemented for the first time on a larger scale this spring at the Boudry family farm in Ypres. "In an open field, we grow around 24 hectares of leeks every year. Thanks to our cooperation with Inagro, we started experimenting with hydro leeks in a small basin on our farm in 2022. The advantages soon became clear," says farmer Bart Boudry. "Growth is fast, the product is crisp, and labor requirements are lower. We truly see a future in this."

The new large-scale basin was designed with energy efficiency, sustainability, and advanced technology in mind. The first plants entered the water at the beginning of July. In the coming seasons, the system will serve as a reference point for further optimization, demonstrations, and knowledge sharing.

Sustainable, profitable, and export-ready
The cultivation carrier was developed by Hydromasters, commissioned by REO, and in collaboration with Inagro and Indurra. In 2022–2023, Indurra, with support from Vlaio, also built the first prototype of a harvesting robot, which will be put into operation later this year in the shed next to the basin. This robot will automatically harvest and process the leeks, making the system scalable for field deployment.

"The trials showed that the cultivation is profitable, even when factoring in the investment cost," says Rik Decadt, manager of study services and sustainability at REO. "The positive results of taste and storage tests confirm the quality of the final product." The leeks are also completely free of soil particles, creating additional export opportunities to markets such as Canada and Japan.

Importantly, this new cultivation system does not replace conventional leek cultivation but complements it. "Production in open field and on carriers can perfectly coexist," concludes Filip Vanaken, general manager of REO. "REO remains fully committed to both systems and supports growers in their choices."

Future for (hydro)leeks in Flanders
Today, around 3,650 hectares of leeks are grown in Flanders, 85% of which are located in West Flanders. Of this West Flanders area, 2,200 hectares are for the fresh market and 900 hectares for processing (source: REO). The sector provides hundreds of jobs and is an economic pillar for the province.

Bart Naeyaert, West Flanders' deputy for agriculture and horticulture, sees hydro leeks as a strategic accelerator: "West Flemish growers have been bringing top-quality leeks to market for decades. With hydro leeks, we show that craftsmanship and innovation go hand in hand here. This is part of the leek sector's tradition of innovation. The first leek harvesters, leek washing installations, and leek planting machines all originated in West Flanders. Now we are investing in a sustainable cultivation system, improving working conditions, and keeping added value in our region. This is no longer an experiment – this is scalable innovation."

Demonstration on 26 August
Growers considering hydro leek cultivation will soon be able to see the new growing system for themselves. On Tuesday, 26 August at 13:30, the Boudry family, Inagro, REO, and Hydromasters will host a demonstration afternoon at the farm in Ypres. Farmers and other interested parties will be given a tour of the cultivation system and its technology. Registration is required and can be completed via this link.

Cultivation manual for hydro leeks
To provide optimal support for growers, Inagro has developed a comprehensive, practice-oriented cultivation guide. This guide compiles all the insights from four years of research – carried out as part of the Vlaio project 'HydroLeek' – and offers concrete tools for anyone looking to start outdoor hydro leek cultivation. From system selection and fertilisation to plant density, crop protection, and harvest planning, every aspect of cultivation is covered. The manual will be distributed at the demonstration afternoon on 26 August and will be available for free on Inagro's website afterward.

For more information:
Inagro vzw
Ieperseweg 87
8800 Rumbeke-Beitem, Belgium
[email protected]
www.inagro.be