"Hydroponic cultivation not an option for specialty crops"

At Tuinderij J. v.d. Berg en Zn in Ridderkerk (Netherlands), Jan and Albert-Jan van den Berg - father and son - cultivate leafy vegetables under glass. There are different crops spread over the four hectare greenhouse, divided over three locations: you will find anything from turnip greens and lettuce to endive and purslane. The produce finds its way to consumers through various trading companies in Barendrecht.

Cultivating on demand
"Based on what customers request from us, we make a plan for the crops we are going to grow, and by alternating the crops, we also take the soil resistance into account." Over the years, the van den Berg family has gained a lot of experience. "We really have grown a lot of crops, sometimes a crop will be dropped and others will be added."

In addition to the crops being cultivated for their customers, in the summer months they fill 1 to 1.5 hectares of the greenhouse with spinach seeds as a partner of Rijk Zwaan. "This is how we are part of their propagation program."

Chinese vegetables
Specialty crops are the true strength of the Ridderkerk nursery. In addition to traditional types of lettuce, the company also cultivates Chinese leafy vegetables. "At the moment we are growing four varieties: in 2009 we started with choy sam, followed by pak choi and then a type of Chinese lettuce."

Mak choi was the latest addition, a popular Chinese lettuce. "The customers prefer a thick stalk that they can cut and eat in slices. The leaf is also nice to eat."

According to Albert-Jan, the cultivation of Chinese vegetables can be challenging. "The varieties have not yet been bred as strong as Western European vegetables, so they are less resistant to climate conditions in the Netherlands and they are more prone to disease." As a grower, you have to be very alert about watering and fertilizing.“ There isn’t as much knowledge yet about these crops. "In terms of crop protection, there are fewer guidelines, which also makes it difficult." As far as Chinese vegetables are concerned, you have to figure it out on your own as a grower", Albert-Jan concludes.

No hydroponic cultivation
Leaf vegetables grow in soil at Tuinderij van den Berg, although he has noticed that growing lettuce hydroponically is gaining in popularity. "The customer thinks that this is cleaner and less environmentally harmful, so we will have a little less lettuce and focus more on specialty crops."

It's a conscious decision to continue growing crops in soil: "For us, growing on water is not yet an option. For many of our crops no suitable cultivation systems exist yet. Also, the cultivation of purslane and turnip greens is short, for example. You sow it and you harvest it, if you start growing it on water, there is a lot more work involved.

"Moreover, if we choose to grow on water, we limit ourselves in the possibilities of alternating crops. Instead of going into that direction, we are focusing more on traditional cultivation. We are always open to requests from customers who want to grow a specialty product in the summer or winter, or would like to grow a long forgotten vegetable in the Netherlands."

For more information:
Tuinderij J. vd Berg en Zn
Albert-Jan van den Berg
info@tuinderijberg.nl
www.tuinderijberg.nl