Ronald van der Salm (of Pure Gerbera)
"Since the beginning of this year, I have switched to Earthwool® rock wool cubes for part of my mini gerberas. For some time now, there has been a trend in gerberate cultivation to switch from coconut to this innovative growing media." (The production of Earthwool® is done without a formaldehyde-containing binding agent).
Ronald decided to partially transfer his over three hectare gerbera nursery to Earthwool®. This enabled him to properly compare the results. The flowers of these plants have been harvested since several months. Ronald: "The thing I noticed first was the better capacity of these cubes to retain moisture. To me, it is an enormous advantage the cubes stay more moist, especially during the summer. This results in a larger water buffer, e. g. in the event of the water supply malfunctioning".
According to Van der Salm, the biggest advantage, however, is the durability of the stone wool cubes. They last much longer compared to the coconut he used before. Van der Salm: "The durability of coconut is approximately two years. I can grow on stone wool much longer, considering it will last for three to four years. For me that's where the financial advantage is. In two years time when the coconut is finished, there is a great chance I will completely switch to these rock wool cubes".
On an area of 33,200 m2, PURE Gerbera grows large-flowered (9,000 m2) and mini-gerberas in Delfgauw, integrated and in a sustainable manner. The company is Netherlands first to supply fully biologically grown plants. Via Delfgauw, the products find their way to the entire European market. Over 20 million stems of gerberas reach consumers, mainly through wholesalers. Year-round, 40,000 high-quality flowers leave the Delfgauw company each week.
Together with his wife, Michel Sies owns the Gerbera company Sies van der Spek. It covers an area of 15,600 m2 on the Anthony Lionweg in Bergschenhoek. The pots now hold mini-gerberas in 14 colours. These have been carefully selected. Michel and his wife are not only guided by colour, but also pay attention to the returns throughout the year. Some species give more flowers in winter than others. They also make sure the flowers are easy to pick. The plants are therefore in pots, filled with stone wool blocks. "Especially the rapid rooting is a big advantage with the Earthwool blocks. The firmness is good and we are working on sustainability," according to an enthusiastic Sies van der Spek.
From: Berkel en Rodenrijs
Klondike Gardens, based in Berkel and Rodenrijs, is a nursery specialised in the cultivation of gerberas. The nursery consists of two departments with a total area of 42,000m2 and is owned by the van Leeuwen family. Ruud van Leeuwen: "At Klondike Gardens we produce high quality gerberas while paying attention to the environmentally friendly way in which we want to do this". The latest techniques are used to produce the gerberas. Also Klondike Gardens has launched a major experiment. Cultivating happens in containers filled with stone wool cubes. "The roots make use of the total volume and are looking good. The Earthwool Cubes properly meet the requirements, are solid and are an airy substrate".