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 gerbera cultivation to switch from coconut to this innovative growth media.’ (Earthwool® is produced without a formaldehyde-containing binding agent).
Ronald decided to partially switch his more than three hectare gerbera nursery to Earthwool®. This enabled him to properly compare the results. The flowers of these plants have been harvested for several months now. Ronald: ‘The thing I noticed first was the better capacity of these cubes to retain moisture. To me, it is an enormous advantage as the cubes stay moister, 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 rock wool cubes. They last much longer compared to the coconut he used previously. Van der Salm: ‘The durability of coconut is approximately two years. I can grow products on rock wool much longer, as 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 in Delfgauw, PURE Gerbera grows large-flowered (9,000 m2) and mini-gerberas, in an integrated and sustainable manner. The company is the first in the Netherlands to supply fully biologically grown plants. From 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 site 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 that have been carefully selected. Michel and his wife are not only guided by colour, but also pay attention to the yields throughout the year. Some species produce more flowers in winter than others. They also make sure the flowers are easy to pick. The plants are therefore in pots, filled with rock wool blocks. ‘The rapid rooting in particular is a big advantage of working 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 sections with a total area of 42,000 m2 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.’ We use the latest techniques to produce our gerberas. Klondike Gardens has also launched a major trial in which cultivation is done in containers filled with rock wool cubes. ‘The roots make use of the total volume and are looking good. The Earthwool Cubes meet our requirements and provide a solid and airy substrate.’