Biodiversity is of great importance, but the mowing policy is a point of discussion

Text: Nursery Stock Trade Fair GrootGroenPlus BIODIVERSITY IS OF GREAT IMPORTANCE, BUT THE MOWING POLICY IS A POINT OF DISCUSSION

Biodiversity is very important. Growers and governments agree on this. However, when it comes to the mowing policy, major differences of opinion remain. There are also differing views within the growers’ community itself. Are nursery municipalities actually aware of the additional biodiversity that the various crops bring, and which crops provide the most biodiversity? And what influence does the ‘let it grow and spread’ policy have on cultivation in the area? GrootGroenPlus discussed this with the Agro Biodiversity Work Group of Treeport and the ‘tree nursery municipalities’ of Zundert and Boskoop.

Last year, many municipalities in West Brabant – including Zundert – decided to mow their roadsides and ditches in a different way. This is done in a collaboration between 13 municipalities in Western Brabant, the Brabant Delta water board, the State Forestry and the Bijenlandschap (bee landscape organisation). The main reason is that all participants want to mow ecologically and bee friendly. The biggest change brought about by this decision is that the roadsides and ditches are mown less often. By protecting nature and the habitat of various insects, biodiversity in the area should be improved.

Growers of nursery stock are the natural partners in the pursuit of biodiversity. In this context, Treeport has created the Agro Biodiversity Work Group. We spoke with chairwoman Jolanda van Hasselt about the purpose of this work group and about the way in which you can strive for greater biodiversity in cooperation with the governments. “Knowledge about agro biodiversity is limited and fragmented when it comes to growing nursery stock,” says van Hasselt. Increasingly more growers see that a natural balance can have a positive effect on the growth of trees and plants and that sicknesses and plagues need to be fought in different ways than only chemical. However, these growers often lack practical tools to deal with this. We want to use the work group to combine all existing knowledge, both scientific and from experience, and put it into practice. The pursuit of a greater degree of biodiversity is not new. Jolanda van Hasselt: “Actually, we have been working on this for many years. A number of growers started sowing flower mixtures as soil fertilizers in corners or empty pits instead of spraying everything with a weed control substance or keeping the soil nice and black with a machine. And we feel that more growers should join that pursuit, or even better: every resident in Zundert and the surrounding area.

Van Hasselt: “As growers of nursery stock, we grow a product that contributes pre-eminently to biodiversity. Therefore, I think it is of the utmost importance that the government and local authorities consider us a partner in this pursuit. And that’s what’s missing sometimes.” The mowing policy turns out to be a hot topic. By refraining from mowing, the herbs get the opportunity to spread. That’s nice, but not if your nursery land also gets the full layer of those scattered herbs. “For growing standard tree, that isn’t much of a problem,” says Van Hasselt, “however, for nurseries with seeds, it’s disastrous in the spring. The beautiful flowery roadsides are not the problem, but the many seeds that blow over and end up between your plants cause a lot of misery. Buyers still want to receive plants without additional weeds. Sometimes, we feel like we cannot win. First, we were obliged to use weed control products, and now we get a fine if we control the weeds. It would be nice if municipalities and water boards realized that growers have the expertise when it comes to management, that they also have a spraying license and that they don’t get paid for weed management.” Van Hasselt notes, however, that some progress has been made. What used to be absolutely non-negotiable is now becoming negotiable. “All parties must clearly indicate where the problem lies and then try to find the best solution. Tree growers also find biodiversity of great importance and often contribute to this through their cultivation.”

The diversity of species and varieties produced in the tree nursery municipalities contribute to increasing biodiversity in those municipalities in a positive way. The shelter, the food supply, the opportunity to migrate and to nest etc. all differ among crops, but the total picture is overwhelming and of a much higher value than is often seen now. It is a combination and teamwork of organisms and plants.

On behalf of trade fair GrootGroenPlus: Chantal van Kuyck, trade fair manager.

“On 16 November, the national celebration of ‘Stichting Nationale Boomfeestdag’ will take place in Zundert. This is a unique, massive event, with a lot of attention for biodiversity. GrootGroenPlus has been an active partner of this foundation for more than 10 years. Taking into account all stakeholders

At the time of writing this article, the new board of mayor and aldermen had not yet taken office in the municipality of Zundert. However, the municipal organisation considered it to be very important to reflect the municipality’s

The Dahlia is also common in Zundert.

biodiversity policy in the KwekersBode. “The municipality of Zundert is aware of the importance of the nursery stock industry for biodiversity in the municipality,” said a spokesperson. “That is why we are constantly in close contact with this industry. We are looking for the middle ground, something that would be in the best interest of both parties. This could be: increasing biodiversity through ecological roadside management and limiting the nuisance caused by weed seeds blowing in at growers/farmers. We have to take into account all our stakeholders when it comes to biodiversity. In addition to the nursery stock industry, these are, for example, our inhabitants and nature and environmental associations.”

The municipal biodiversity policy (mowing policy) may sometimes clash with the interests of growers. This is certainly something the municipality is aware of. “We understand that ecological mowing management can have negative consequences for our growers/farmers. That is why we tried to find a solution along with ZLTO, Treeport, and Bijenlandschap West-Brabant. It is important that we achieve ecological goals, without much nuisance from weed seeds blowing in for our growers/ farmers.” Normally self-management of roadsides is not allowed, now it has been decided to allow this in some locations. The relevant locations and the conditions attached to them can be found at: www.bit.ly/zelfbeheer-toegestaan.

How could the municipality, the water board and growers best cooperate in this area? According to the municipality, this is: “by remaining in conversation and having (and keeping) an eye on each other’s interests. The Bijenlandschap West-Brabant is also a partner in this. In addition, it is important to properly monitor and evaluate the impact of this policy, including the possibility for growers to intervene themselves, to do the right thing in the future.”

Putting more focus on the planting of new trees

We also went to see how another municipality with a big tree nursery industry looks at this. Boskoop is one of the nuclei of the municipality of Alphen aan den Rijn. “The importance of biodiversity is not in question in the municipality of Alphen aan den Rijn,” says alderman Anouk Noordermeer. “There is a lot of focus on this in our ‘green and trees’ policy. The new college has been instructed to make a firm commitment when it comes to planting new trees. In addition to a diverse use of as many non-toxic plant species as possible with different flowering times, our tree policy sets the ambition to manage 1,000 different species. Increasing biodiversity is also mentioned in the Environmental Vision and the Sustainability Implementation Agenda. In the municipal mowing policy, the municipal management of rough grass and bee idyll classes is designed in such a way that the optimum conditions are created for insects”.

Alderman Noordermeer says that intervening in nature with management or by combating harmful herbs or unwanted insects or soil life is at odds with the great importance of biodiversity. “This interest sometimes clashes with the importance of the floriculture sector to protect products. At nurseries, we therefore endeavour to coordinate the mowing policy in consultation with growers in such a way that nuisance is avoided as much as possible. But the overflowing of seeds is not 100% preventable.”

“Biodiversity, and plant diversity in particular, prevents the occurrence of entire pests,” says Noordermeer. “By introducing diversity into the plant world, a balance is created in the insect world. We therefore also want to focus on increasing the number of insect hotels. This helps the growers, because a plague more often happens at nurseries, since they often have many plants of one species. Preventing the plague in a natural way is important. In addition to aligning the mowing policy, it is therefore very important to focus on plant diversity and insect hotels, and this is something in which we as a municipality and growers work together.” 

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