Greenhouses that used to be filled with fruit-bearing vegetables are now home to various cabbage crops, along with onions and leeks. These plants aren't grown for harvesting, but for producing seeds. Former chrysanthemum grower Bastiaan Borst and his son Timo have started this seed production in the greenhouses in Sexbierum, the Netherlands, on a notably large scale, an operation that covers 13 hectares in total.
Bastiaan and Timo Borst, father and son in seed cultivation
Before beginning seed cultivation, the greenhouses had to be cleared after being purchased at the end of 2023. Significant investments were then made, primarily in water technology and insect screens. For Huisman Scherming, this was considered a "mega project." Grower Bastiaan recognizes that he and his son's work in northern Friesland is unique, as seed cultivation on such a large scale is quite rare in the Netherlands.
Cabbage in bloom
An enterprising son
Bastiaan began his venture into seed cultivation in 2016 in Heerhugowaard, where he previously grew chrysanthemums. Looking for a larger space to meet the seed demand from a breeding company, the Borst family moved to Sexbierum, where they found empty greenhouses that had belonged to the large cultivation company Hartman. Bastiaan and his son succeeded in purchasing two of these greenhouses, setting one up for organic cultivation and the other for conventional cultivation.
Celery
In mid-May, Timo is not around as he is temporarily in the U.S. for work involving peonies. "My son is an enterprising young man, a real doer," Bastiaan says proudly. "As a kid, he even bought Christmas trees to sell." After completing his agricultural vocational training at Vonk, he joined his father as a co-entrepreneur. They both own the nursery named Floris. "I wouldn't have taken this step without my son," Bastiaan admits, who also relocated to a nearby village to be closer to their seed cultivation business.
To prepare the ground for seed cultivation, a green manure crop was sown in the greenhouse, which was previously used for conventional cultivation, and then mixed with the soil
Quails and grain pollen
In mid-May, the crops we see in one of the two greenhouses were planted the previous August. Before planting, work was done on the greenhouse and its soil. "In the organic greenhouse, we didn't need to do much to the soil since it already contained a lot of organic matter. In the other greenhouse, we sowed a substantial amount of green manure, which we then shredded and mixed into the soil," explains Bastiaan.
As you walk through the greenhouse, you may notice quails foraging among the plants. "That's my son's project," Bastiaan explains. "The quails search for and eat caterpillars among the leeks." You'll also see grain pollen scattered in some areas between the crops. This is also part of their biological control strategy, as the grain pollen serves as host plants for aphid predators.
Fennel
Insect netting
Some of the crops have already started flowering. When Bastiaan opens one of the closed greenhouse sections with red cabbage, he sees the familiar sight of bamboo sticks supporting the bolting plants. The focus here is on seed production. "We grow three types of red cabbage," Bastiaan explains. "Different growing regions need different varieties."
The insect screens here are important to ensure proper pollination. Huisman Scherming has installed 7,000 air vents with Simplefold insect screens, set up 35 intermediate barriers over 100 meters each, and fitted 374 ridge screens. This setup helps protect the crops while allowing necessary pollination.
To keep the different cabbage varieties separate, they are divided by intermediate walls with zippers. As we walk along the concrete path, we see fennel, carrots, and onions. In these areas, the use of flower netting is noticeable, similar to what is used in chrysanthemum cultivation.
Flower netting with onions
Different from chrysanthemums
With 13 hectares, the seed cultivation operation is quite significant, yet manageable with a small team. "It's different from something like tomato seed cultivation," Bastiaan explains. "In that case, each flower needs to be pollinated by hand. For us, seed cultivation flows smoothly at this scale. It's more stable, especially in terms of revenue. In chrysanthemum growing, you experience very good years and very bad ones. Seed cultivation is less volatile, making it more enjoyable to work with." Bastiaan and Timo have embarked on a rewarding journey in Friesland.
For more information:
Floris Sexbierum
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