The site is taking shape nicely. In Amstelveen, the Netherlands, a new 3ha greenhouse is being built for Ko Kolk Hortensia. It will be used to grow and propagate cut hydrangeas. The new greenhouse will comply to all modders requirements, because, according Bartjan Kolk, only top quality is good enough.
The cultivation of cut hydrangeas has become more professional over the last years, he explains. In the last 15 years, not only the production of cut hydrangeas increased, the quality improved as well. Due to the good propagation, partly thanks to Kolk's contribution, the product has become more mature and more fused into the assortment at the florist, trade and exported.
Levelling the ground
From very good to excellent
Regarding the new construction, the first thing one notices is that there stood quite a new greenhouse at this spot. Kolk often hears that he demolished the newest greenhouse in the street, however it's done with a reason. "I was looking for a large land parcel to build THE cut hydrangea greenhouse instead of rebuilding an existing greenhouse and make concessions. On top of that, I want to use it for the coming 25 years and I therefore want to start as future proof as possible."
One of the air handling units
After a challenging start, the construction is now picking up pace quickly. The start of the project was slowed down by a winter full of rain. Till mid-march one could not walk on the site, you would be in the mud until your knees. Afterwards, during some nice weeks, it dried, but the ground became as hard as concrete. All glass is on the greenhouse and the technical equipment is being installed. For example, a double screen and an air handling unit has been installed recently. "They enable to dehumidify the climate in the greenhouse, which will be particularly beneficial in fall. We are learning to cultivate in a totally different manner, but with this investment, we will be a step ahead of the competition."
No gas connection
The biggest asset is the heat and cold storage in the ground, a system that the previous owner already had and which Kolk could take over. In summer time, cool water will be used to cool and/or to dehumidify and the heated water will go back in the ground. In winter time, it works the other way around. Then, the warm water will be used (and upgraded by a heat pump) and will go back into the ground when it's cooled. So, no gas connection is needed anymore.
The greenhouse has an aisle of 180 meters. Compared with the old greenhouse, the amount of meters that can be used for breeding/propagation have been doubled. According to Kolk, this will make it easier to get a realistic picture during trials regarding discovering the potential of new varieties. Optionally, in the future, they can double the size of the cultivation greenhouse. Regarding the water capacity, Kolk is well prepared as he made the content of the silos twice as large than needed for the first phase. There are two separate water streams as the addition of aluminum makes the hydrangeas turn blue.
In the future, the greenhouse can be expanded with another 3ha.