In the middle of farmland, that's where you might smell an agricultural odor. Cow dung is part of it. And if you live between the greenhouses, you will occasionally smell tomatoes. People in the Netherlands are not likely to complain about it. For a greenhouse in the Hellevoetsluis polder near the Rotterdam harbor, the situation is different. The cannabis grower is under fire for odor nuisance. But is it because it really stinks, or is it mainly fear of an unfamiliar smell?
Max Schreder of CanAdelaar, one of the ten authorized cannabis growers for the Dutch Experiment Closed Coffeeshop Chain, or the Dutch government's cannabis trial, cannot help but feel that the complaints about the smell stem from unfamiliarity with cannabis cultivation.
A whiff of illegality surrounds cannabis cultivation. But in Hellevoetsluis, and in nine other locations in the Netherlands, there is absolutely no such thing. Under the full control of the Dutch government, ten growers are allowed to grow cannabis legally. Every plant, bag, and transport from the greenhouse to the coffee shop is closely monitored at CanAdelaar. Track-and-trace is nowhere in the agricultural sector as extreme as in this cannabis trial.
Late to the party
CanAdelaar was initially not even going to participate in the cannabis trial. It just fell outside the license draw. CanAdelaar ended up as number 12 on the list. When two parties turned out not to be able to participate after all, the company, with Austrian owners and experience with cannabis cultivation at home and in Canada, was still allowed to start. "We were late to the party," Max says.
The Commercial Director understands Dutch well and is also well-versed in Dutch politics. This is evident when he later talks about the agricultural debate in the Netherlands, nitrogen, and 'the BBB', a new, agricultural oriented political party. The agricultural sector in the Netherlands, he knows, is under pressure.
Every plant is labeled, for maximum track&trace
Greenhouse rapidly converted
Initially, there was a rush to get the cultivation site ready after receiving the cultivation license in March 2023. The tomato greenhouse in Hellevoetsluis was quickly converted. Greenhouse builder Horti XS was in charge of this. "When it became clear that the mother plants would soon arrive, we worked with about 60 men at a time to get the greenhouse ready for that," Project Manager Sebastiaan Hijstek and Dennis Flaton, COO of the greenhouse builder point out.
During a tour of the company, Max also repeatedly stresses how special it is what we can already see in mid-February. Two of the three greenhouse compartments in the complex, about two hectares in total, are already full of cannabis plants. The third compartment is being prepared during our visit. HPS lamps are being installed, and an air filtration system also passes by on a cart to be installed. This is a system with ASPRA® technology, supplied by VFA Solutions.
Air filtration with system VFA Solutions
Contact with neighbors
At the start of cultivation, these systems were not yet in place. However, the entire irrigation system, for example, had already been modified by greenhouse builder Horti XS so that irrigation water could be collected and recirculated. The tomato greenhouse became a greenhouse for potted plants, only slightly different. The fact that odor nuisance could be a problem with cannabis cultivation had not been realized soon enough at CanAdelaar, Max admits.
Yes, they had communicated with the neighbors since the beginning about their plan to convert the greenhouse from growing tomatoes to growing cannabis. Today, many locals also work there, including the former tomato grower himself. Still, complaints came to the environmental department. The service, the DCMR, keeps track of complaints for the entire municipality of Voorne aan Zee, under the smoke of the Botlek. Sometimes there are 100 in a week, sometimes 10, and during our visit, about halfway through the week, there is one.
Whether that complaint is about CanAdelaar or one of the many chimneys in the port area cannot be seen on the public reporting website. Max can hardly imagine that there are still many complaints about his company. In response to odor nuisance, CanAdelaar immediately decided to invest heavily in air filtration systems. A total of 72 are currently installed, with more to be added. "It has cost millions to realize that well," stresses CanAdelaar's Commercial Director. "If it didn't work, we wouldn't do it."
Once the crop starts flowering, it is time to harvest. Year-round, the company employs 100 people. That is substantially more than was previously needed when growing tomatoes in the same greenhouse.
Propagation, cultivation and processing in one company
Anyone entering the cannabis greenhouse smells virtually nothing. Even outside, arriving at the greenhouse, was like that. The first greenhouse compartment is set up for long-day treatment. With maximum, mostly free sun light from outside supplemented by artificial lighting from (for now) HPS lamps (LED is an option in the future), the plants can grow well.
Once it is time for them to flower, the plants move to a greenhouse compartment for short-day treatment. Here, greenhouse builder Horti XS has installed blackout screens, among other things, so that the plant can sense that the days are getting shorter.
After many processing steps, you get cannabis ready for the coffee shop. What is special is that CanAdelaar does all the steps of the process itself, from the propagation of plant material to harvesting, drying, processing, and packaging. For this, the former tomato shed has been converted into numerous (air-conditioned) compartments. Again, in record time. Max says, "We are quite proud of how our plan from Excel turned out in practice."
Follow-up cannabis trial
When on April 7, 2025, finally after much delay, the official four-year experimentation phase begins, CanAdelaar will be the only grower cultivating entirely in a greenhouse. Max explains that the Austrians wanted to keep costs as low as possible. CanAdelaar opts for a low CAPEX. Indeed, whether legal cannabis cultivation in the Netherlands will be allowed to continue after 2028 is not yet clear. The Hellevoetsluis-based growers want to grow a high-quality product at the lowest possible cost. A real convenience product, in other words, just like the tomatoes used to be.
In Hellevoetsluis, they managed to be first in production despite the late admission to the experiment. "We now supply almost all 73 participating coffee shops," Max points out. "In volume and turnover, I think we are the market leader."
In time, he expects an oversupply in the cannabis trial. That, he knows, has also happened, for example, in California and Colorado. "Cannabis grows like weed," he jokes. "There's a reason they call it as such."
It is another reason why the company chooses to keep costs low. Especially the (over)regulation by the Dutch government makes cultivation expensive. The topic of track and trace comes up repeatedly. "Much needed, but due to the form chosen by the government also a nightmare," according to Max. A lot of manual work is involved in all the administrative operations.
Labels for track&trace
Five types of products
What helps growers in Hellevoetsluis keep costs down, besides choosing to use natural light, is that the greenhouse complex is connected to geothermal heat. That geothermal heat comes from a project in nearby Vierpolders. There is also a CHP in the greenhouse. This generates electricity for the HPS lighting, and the various systems for processing the cannabis, from flower to bagged cannabis, also require electricity.
Despite its preference for large-scale, convenience cannabis cultivation, CanAdelaar will also start making specialties later this year. Some of the harvest will be processed into edibles. "There is demand for that, and none of the other participating growers can make it. That's why we decided to do it anyway." Alongside weed, hash, concentrates, and pre-rolled joints, those edibles will soon be the fifth end product from the greenhouse, which grows more than 30 different varieties.
CanAdelaar does everything in-house, from propagation to cultivation and processing for delivery to coffee shops participating in the Dutch government's cannabis trial
Vent
It is mainly the terpenes that give cannabis its recognizable, strong smell. VFA Solutions' systems filter gases and odors from the air. The system also removes (ultra)fine dust from indoor and outdoor air. Vincent van Baaren of VFA Solutions explains: "Our technology combines ASPRA® technology with specific adsorption material. At CanAdelaar, we test four types of adsorption material to choose the optimal product configuration for these greenhouse conditions. In projects with cannabis in Portugal, the U.S., and Canada, we already have experience with two types of absorption material, but we think we may have found two more materials that can also work well."
The electrostatic air filtration technique is powerful, effective, and sustainable, Vincent says. "It is possible to save up to 80 percent on energy costs of ventilation systems with our systems because our filtration systems have an open structure and do not clog." The growers in Hellevoetsluis do ventilate occasionally to get rid of moisture from the greenhouse. The availability of geothermal heat helps get moisture out of the greenhouse. Apart from air filtration systems, we don't come across any dehumidification units. Max says: "Opening the windows occasionally is the best way, and the cheapest."
Dennis Flaton (Horti XS), Vincent van Baaren (VFA Solutions), Sebastiaan Hijstek (Horti XS) and Max Schreder (CanAdelaar)
Air filtration
ASPRA air filtration technology was originally developed for medical care but is now used in many sectors, including horticulture, especially cannabis cultivation. Vincent says: "Besides gases and odors, we remove fungi, pathogens, microbes, bacteria, viruses, and endotoxins from the air. In horticulture, think, for example, of Botrytis and mildew. In the greenhouse, these can lead to a reduction in yield and product quality, as well as higher crop protection costs."
Together with Horti XS, VFA Solutions devised a plan for the CanAdelaar project. VFA Solutions' first units were installed in Hellevoetsluis last autumn. CanAdelaar placed a hefty order to solve its problems. Vincent: "I think it's great to see here now in practice that whatever has been proven in the laboratory also works. Smell for yourself."
Importantly, in a greenhouse environment, the air filtration system also works under humid greenhouse conditions. Vincent explains: "HEPA filters do not work optimally under such conditions and can clog up more easily. Our technology does not have that problem. We tune the closed ionization to the air composition. The closed, controlled ionization we work with in our systems is unique."
Fair treatment
What VFA Solutions does at CanAdelaar can be done for the entire agricultural sector, Vincent assures us. For the agricultural sector in the Netherlands, however, Maximiliaan hopes that, because of complaints about odor nuisance, this will not be necessary. As far as he is concerned, agricultural activity sometimes involves an odor, whether from cow dung, a tomato crop, or cannabis. "Our entire complex is still being equipped with air filtration systems. We are very satisfied with VFA Solutions' systems. You can hardly smell cannabis here in the greenhouse now. That's why we are now also asking for fair treatment and are challenging the fines we receive."
For more information:
CanAdelaar
Maximilian.Schreder@canadelaar-og.nl
www.canadelaar.com
Horti XS
sales@hortixs.nl
www.hortixs.com
VFA Solutions
vincent.vanbaaren@vfa-distribution.com
www.vfa-solutions.com