After having grown roses for 30 years, Jan van Weerdenburg switched to growing cut hydrangeas 4 years ago. The harvest season of his new crop is between June and December. This differs from the year-round harvesting of roses. This gives him more time for his other passion; taking care of his own "zoo" which includes Alpacas, mini kangaroos and many kinds of birds.
In the winter, heating is only used to keep the greenhouse free of frost. In the summer, the greenhouse temperature shouldn't exceed 25⁰C and the overly harsh sun must be filtered out. This spring, the light-diffusing climate screen New HARMONY 4215 O FR was installed. Jan explains that this is his 3rd Svensson climate screen in his 34-year old greenhouse. His first screen was the “LS11”, followed by "ULS 14" 15 years later, and now, 19 years later, the HARMONY.
His first experiences with HARMONY: "The greenhouse climate feels very nice". He adds: "The light in the greenhouse isn't sharp, it doesn't hurt my eyes; the climate is even, there is no draught, I see soft shadow lines." The HARMONY is closed when the outdoor sun radiation is higher than 600 W/m2. Unlike his old screen, the HARMONY 4215 O FR has an open structure. This allows the operation to completely close the climate screen without compromising the exchange of air above and below the screen.
Because no ventilation gap is necessary, the sun doesn't have a chance to shine directly onto the crop, "Thanks to this, I don't have anymore sunburned hydrangea branches," Weerdenburg is pleased to note. This past Spring has been warm, but it hasn't been hotter than 25⁰C in the greenhouse thanks to the HARMONY climate screen. In the summer, additional chalk is used on the the greenhouse cover. The moment of chalking was postponed by a few weeks this year because of the ability to regulate the greenhouse temperature so well with the diffuse HARMONY screen. As such, the hydrangeas cumulatively receive more light.
As Jan walks around under the high-quality light-diffuse screen in hisgreenhouse, he sometimes thinks back to his first growing experiences in a rented garden with gypsophilia. Hammered glass covered this garden, which also diffused the light. At the time, this already resulted in longer stems. This is promising for the hydrangeas this year, he says meaningfully. He hs already had growers over to visit and just like Jan, they feel the pleasant greenhouse climate under New HARMONY