If you ask a Rotterdam resident about the Binnenwegplein, there’s a high chance they’ll start talking about the Donner-plane tree. This iconic plane tree (Platanus x hispanica) from 1947 still stands proudly in the cityscape in the central area of Rotterdam. A lot of construction and renovation is happening in the center of Rotterdam to meet the demand for shopping areas and housing. This has led to the need to address the public space with its trees and greenery, and to improve and beautify it where possible.

TreeParker Tree Bunker System

Various parts of the city of Rotterdam have undergone a metamorphosis in recent years, such as the Binnenrotte and the Coolsingel. Following this, the city is also trying to improve other places and streets; this includes the Donner-plane tree. In this project, the existing tree is being provided with a sustainable climate-adaptive growth site layout using the TreeParker tree bunker system. With the TreeParker system, which creates a ‘forest situation’ in the city, the rich tree bunker soil in the system is completely relieved from the user pressure of the shopping area and this soil does not become completely compacted. As a result, the existing roots can root in the tree bunker soil, so that the tree can grow healthy and sustainably. By providing 30 m3 of rootable growth volume in the 90 cm deep TreeParker system, against the current root package, it is ensured that the Donner-plane tree can keep going for decades. This 74-year-old iconic tree is ready for the future and can perform its many functions well and healthily again. In the middle of the city, the tree is busy capturing CO2 and fine dust, it can be a ‘home’ for our ecosystem services and much more.

Working in the Central Area

The project was carried out at the end of October 2021 by the tree specialists of Idverde Bomendienst and Idverde Realisatie, Bruinisse branch, on behalf of the municipality of Rotterdam. Idverde has a lot of experience with the installation of the tree bunker system. The digging and sucking away of the old soil, the installation of the TreeParker system, the filling of the tree bunker system, and related work took a week. As this project involves an existing plane tree, the old soil was carefully sucked away first, causing as little damage as possible to the roots of the tree and the utilities. Subsequently, the ground around the tree was carefully removed with a crane to make room for the TreeParker tree bunker system. Because many utilities run through the Binnenwegplein, a zone was determined in consultation with the client in advance where there was sufficient space for 30 m3 of extra growth volume, with as few obstacles in the growth site as possible. A limited number of cables in this project run around and over the tree bunker. Of course, in most cases existing cables and pipes can be integrated into the system, if necessary.

The Donner-plane tree on Binnenwegplein forms the center of the shopping area. Therefore, the work had to take place on a small area, safely cordoned off with construction fences. Also, the delivery of materials, such as the tree bunker soil, the TreeParker system, and foundation material, had to be done in small quantities directly with the grab truck. Such projects in urban areas are extra complex because the safety of the shopping public must be guaranteed, access is difficult, and the work must be done quickly and smoothly to minimize inconvenience.