In April of last year, the high-tech greenhouse facility of the newly established Rheinlandgemüse Hydro & Co. was put into operation. Thanks to unique hydroponics, fresh lettuce with root balls now thrives on the approximately 2.5 ha greenhouse area in Vettweiß twelve months a year. The driving force behind the modern lettuce operation is the young grower Elizabeth Graaff. During an on-site tour, she spoke about the emergence of the operation and the potential of the hydroponics cultivation method.
In so-called gutters, the young plants are raised to marketable salads in about four to six weeks, depending on the specified piece weight. "The cultivation method allows for 100 percent area utilization and a maximum level of efficiency and predictability in cultivation. The closer to the harvest time, the more space the salads need and the larger the distances between the gutters. This means, in practice, that we do not give the lettuce more space than it actually needs. We grow as the size of the salad grows, while in open-field cultivation, planting is already done at the final size of the salad." The same applies to the floating system, which is also often used in greenhouses and where the distances between the plants within the styrofoam plate are also prescribed from the beginning.
Competitive Advantage in Winter
Not only from a cultivation technical point of view but also from a sales perspective, the first months after commissioning went particularly well, Graaff summarizes: "The demand for lettuce in Germany is clearly higher in summer. However, we are in direct competition with lettuce from German open-field production. In winter, on the other hand, I have significantly less domestic competition and thus a clear competitive advantage. Selling German lettuce at this time of year is no problem at all; we are also currently completely sold out."
Automation to combat harvest worker shortages
In addition to cost increases, many vegetable farmers are faced with a striking shortage of harvest workers. "For greenhouse cultivation, you can still get people. Of course, I come from an open-field operation, and the work is hardly comparable. There is no heavy lifting in all kinds of weather. Therefore, the conditions for our employees are much better than in the field, so the people who still come mostly prefer to work here. Due to the high degree of automation, the workforce is still important and decisive, but it does not weigh as heavily in terms of costs as in open-field cultivation," Graaff explains. Other reasons behind the creation of the greenhouse were the lack of water resources and the restriction of permitted fertilizers and pesticides in open-field cultivation.
Future potential of German hydro-lettuce
Due to extreme production conditions and weather fluctuations, it is becoming increasingly difficult for many German vegetable farmers to produce a high-quality product, argues the passionate producer. "We too are not completely independent of external conditions, but we can adapt to them more easily and thus deliver a high-quality product in predictable quantities all year round. If there are too few hours of sunshine, we have to calculate whether it is worthwhile to turn on the lighting or simply accept that our lettuce grows slower. But at least we have the option and relatively much leeway to control the microclimate in the greenhouse."
Further marketing potential is also available, according to Graaff. "The interest from retailers is quite large, as the advantages due to cleanliness, durability, and predictability are obvious. Our product is already listed with all major chains and is therefore available nationwide. Accordingly, acceptance by consumers is also rapidly increasing. I also notice this in my circle of friends and acquaintances: A year ago, almost nobody knew the root salad, but that has now completely turned around. Therefore, the product seems to be establishing itself."
Hydroponic cultivation: The trio lettuce grows faster compared to the butterhead lettuce.
View into the seedling department. The seedlings mainly come from neighboring countries.
Fresh lettuce. Currently, eleven people are working full-time in production. Due to the shorter cycle times, more people are in operation in summer.
View of the gutter system
Rheinland Hydrogemüse relies on the advanced gutter system from Hortiplan.
With the help of a robot, salads are transplanted into the larger gutters for the second phase of their growth process.
Trio lettuce, as far as the eye can see. Depending on customer interest, the production of individual varieties (Lolo Rosso/Bionda and Oak Leaf) could also be considered in the future.
The larger the lettuce heads become, the greater the distance between the plants so that they can continue to grow in full.
Head lettuce from hydroponic cultivation. Compared to the trio lettuce, the culture is somewhat more demanding in cultivation.
Thanks to the well-thought-out cultivation system, the microclimate in the greenhouse can be precisely controlled, and fewer personnel are needed than in open-field cultivation or conventional greenhouse cultivation.
Trio lettuce shortly before harvest. Because the hydro lettuce does not grow in the ground, it remains clean compared to the open-field product and does not need to be cleaned after harvest.
Via conveyor belt, the freshly picked hydro lettuce arrives in the processing and packaging department. The lettuce is individually packed in special bags and delivered in EPS boxes to retailers nationwide. Due to the root ball, the lettuce in the bag stays fresh for a few days longer as compared to conventional lettuce.
Born and raised on her parents' open-field operation, Elisabeth Graaff has now chosen hydroponics. This makes her one of the pioneers in German vegetable cultivation.