Wonderwoods, Utrecht: planting trees at spectacular heights

Wonderwoods in Utrecht consists of two green towers with a vertical forest of 360 trees and nearly 10,000 plants, designed to bring urban living and nature together. Biodiversity thrives thanks to the variety of species, while GreenMax root ball anchoring safely stabilises the trees at great heights. Abseiling gardeners maintain the greenery, an approach that has previously proven successful at the Trudo Tower. Wonderwoods is now in full bloom and forms a green eye-catcher in the city.

Wonderwoods: a unique and innovative tower in the heart of Utrecht that combines urban living with nature. With a vertical forest of 360 trees and nearly 10,000 plants, it is set to become Utrecht’s green eye-catcher. Not only is the vertical urban forest beautiful to look at; together, the trees and plants absorb 5,400 kg of CO2 annually and release more than 41,400 kg of oxygen in return.

The Wonderwoods building consists of two green towers measuring 105 and 73 metres in height. The project was designed by Stefano Boeri Architetti, known for the green tower ‘Bosco Verticale’ in Milan, and MVSA Architects. The aim of the Wonderwoods project is to create an advanced harmony between urban living and nature.

On the ground floor, connected to a garden on the sixth floor, there is a ‘Vertical Forest Hub’: a centre focused on documentation and research into urban forestry worldwide. The project is part of the new ‘Healthy Urban Quarter’ in Utrecht – an area of 50,000 to 70,000 m2 intended for living, working and offering cultural activities. In addition to apartments and office spaces, Wonderwoods also features fitness and yoga areas, cycle parking and public recreational spaces.

The towers are enriched with 360 trees and 9,640 shrubs and flowers. As many as 30 different tree and plant species adorn the towers of Wonderwoods. Both coniferous and deciduous trees, including standard trees and multi-stem trees, have been selected for the planting. In total, the urban forest is equivalent to one hectare of lush forest vegetation. Due to the wide range of tree and plant species growing in Wonderwoods, biodiversity thrives and the urban ecosystem is strengthened.

Planting trees on high-rise buildings presents a challenge, as they are exposed to strong winds at such heights. To provide the trees with the necessary stability, the innovative GreenMax root ball anchoring system has been applied. This system ensures that the root ball is firmly held in place by strong straps, allowing the tree to remain stable even in high winds. The root ball anchoring is seamlessly integrated into the planters and covered with a layer of high-quality tree substrate, making it invisible to the naked eye.

In a vertical forest, maintaining the trees is an adventurous and unique task. Abseiling gardeners, specialised in working at height, play a crucial role in maintaining these green towers. The towers are equipped at several points with hooks to which the gardeners can attach their climbing equipment. In this way, the gardeners descend along the building to care for the trees and plants and keep them in optimal condition. This ensures that the vertical forest remains healthy and attractive.

GreenMax root ball anchoring has already proven itself in a similar project: the Trudo Tower in Eindhoven. This tower, located in the trendy and creative Strijp-S district, is 70 metres high, making it essential in this project as well to ensure the stability of the trees. So far, various wind speeds have swept past the Trudo Tower and the trees are still standing perfectly upright.

On Monday 24 April 2023, the first trees were planted in Wonderwoods, an important milestone in the growth of this green icon. Since then, the trees and plants have developed rapidly, and the impressive building is now in full, lush bloom. The vertical forest is truly coming to life and demonstrates how harmoniously nature and urban architecture can coexist.