Published on 28.04.2022

Green Variety, Green Future

An interview with Holger Zahn from Späth'schen Baumschulen: About urban greens, gardening as a craft, the role of arboricultural companies, as well as trees and plants that fit urban environments.

Pines, rock pears and birches. Herbaceous perennials and shrubs. On POP KUDAMM’s rooftops, it is growing and greening. The plants were cultivated and planted by the Späth’schen Baumschulen, a specialist gardening company with over 300 years of history and a reputation for its horticultural and creative designs that goes far beyond the city’ s borders. A Berlin original with a long tradition, where even our grandparents loved to buy their plants. Local business at its best.

There are two reasons why these trees have given POP KUDAMM a green setting: On the one hand, they are real eye-catchers, and on the other, they draw attention to urban greenery and its importance for a city like Berlin. Knowing the positive climate-regulating effects and high quality that urban greenery provides, arboriculture plays a central role in this process – today more than ever. To develop climate-resilient concepts together with urban planners and to help shaping green infrastructures with their expertise.

But what about our city greens? What do we need for green diversity and a green future in Berlin? Together with Holger Zahn, managing director of Späth’schen Baumschulen, we discussed these questions. On a short stroll through Berlin’s green spaces.

Pop Kudamm:When looking at Berlin from the sky, you can see that our city is extremely green. As a horticultural engineer who deals with living materials all day long, do you share this impression?
Holger Zahn:Berlin is definitely a city with a lot of urban greens. That’s why we like to adorn ourselves with the title green city. But if you take a closer look, and also at other cities, especially smaller ones, you can see that we also neglect our greenery quite a bit and don’t put enough love into the details. This is evident, firstly, in the fact that the appreciation of urban greens is much higher elsewhere, and secondly, in the state of maintenance of our greenery, which is not really good in many places.
Pop Kudamm:Do you have an example of this?
Holger Zahn:Herford is a very good example for me. There are lots of green highlights and you can see the appreciation for green spaces. Here in Berlin, on the other hand, there is unfortunately not much to catch the eye. Apart from individual projects, such as here at the Kudamm.
Pop Kudamm:And what do you think is the reason for that?
Holger Zahn:The problem is that while experienced gardeners and landscapers are involved in the planning of urban green spaces, the maintenance is then often left to service providers who don’t know exactly what to look after and how the individual green spaces must be maintained. The gardening profession as a skilled craft is underestimated.
Pop Kudamm:With climate change, tree farms have an essential task and urban planners are attributing a key role to them in fighting climate change. In your view, what is important in green planning in cities like Berlin?
Holger Zahn:Appreciation and diversity. Green space planning today is very often more about resilience and simplicity alone. But green diversity needs more. But for this, more funding would have to be made available and attention would have to be paid to working with specialist companies that can provide the maintenance. It would also be important not to think only rigidly in terms of certified native plants, but also to see the requirements of plants. What is considered native today may not be compatible with its environment tomorrow. This should be taken into consideration. We also must consider that this is a living material that needs time to grow. Especially with trees, which we need for foliage volume, it takes 10 to 15 years just for the planning. And foliage volume is needed for climate regulation.
Pop Kudamm:More trees are also needed for the foliage mass mentioned. Can this increased demand currently be met?
Holger Zahn:That’s right, the current demand is very high. But it’s not just a question of actual requirements, but also of future ones. This is already leading to shortages, which is why the stock should have been doubled 10 years ago. However, this was not possible due to pricing policies in the past. In fact, over 700 tree farms have died in Germany alone over the last couple of years. This cannot be simply compensated now. But where will the plants come from in the relevant quantities? For this, local farms and businesses must be supported more again. Helping more suppliers to come back and the industry to recover more quickly. Tree farms are needed for our urban development because otherwise planning is not reliable.
Pop Kudamm:In many neighborhoods, you can see a lot of small, often private initiatives that take care of urban greens. Can such initiatives contribute to green diversity?
Holger Zahn:Definitely. A tremendous level of commitment is clearly demonstrated in the communities. And you can also see many promising initiatives in calls for bids for new construction projects. Roof gardens are a great example for this. However, this commitment is sometimes only temporary actionism, which unfortunately also flattens if it’ s only dependent on individuals. I think this commitment needs to be channeled and managed.
Pop Kudamm:Looking to the future, as a tree farm, you are thinking about green biodiversity. You are planning some kind of city of the future on a small scale. What exactly is the idea behind that?
Holger Zahn:Various trees will be planted around our tree farm in a residential area that is being developed here. These trees are still rarely seen in the city, but they could shape our cityscape in the future. The idea goes back to the list of 60 trees of the future created by the BdB (Bund deutscher Baumschulen) and the GALK (Gartenamtsleiterkonferenz) and is like a large-scale field trial. For research and to see how these trees develop. When the plans are finished, the residential area will show a variety, with which we want to prove that urban greenery can be different.
Pop Kudamm:Our trees at POP KUDAMM represent just a small part of this. What does the city of the future look like to you in the big picture?
Holger Zahn:Like a place where people like to be. With eye-catchers, green roofs and more space for beautiful plants that are a delight to the eye. With lots of diversity and, above all, good standards of maintenance.

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