The Swiss company Bauer Baumschulen AG has developed a patented system with MobileGreen, making trees available in mobile planting troughs from six metres in height. The key insights from two years of practical operation at various locations and a total of 70 modules installed: Asphalt temperatures drop by up to 32°C in the shade of the trees.
The Problem: City centres heat up and cooling fails due to infrastructure
Densely built-up areas are up to six degrees above the temperatures of their surroundings. On heavily sealed surfaces, surface temperatures climb well above 40°C. On August 18, 2023, asphalt temperatures of over 43°C were measured at the Messeplatz Basel. In autumn 2025 in Reinach, even 50°C due to radiation from glass facades. (BFH, Mobile Urban Green)
The obvious solution - more trees, more greenery - regularly fails in city centres. Underground pipes block planting sites. Building permits are delayed for years. And changing usage requirements make permanently installed infrastructure a risk. The result: The heat remains, the planning continues. Solutions are needed that address the entire issue and thus sustainably change the inner-city climate.
The Measurement Data: Up to 32°C cooler perceived temperature under mobile large trees
Long-term stationary measurements from the Bern University of Applied Sciences in August 2024 show the extent: The perceived temperature (PET) under the trees in MobileGreen planting troughs remained consistently in the comfortable range all day.
The same unshaded area, on the other hand, rose far into the 'very hot' range during the midday hours. In Reinach, the asphalt temperature in the central shade area of the largest MobileGreen tree dropped from about 49°C to 17°C.
Thermal image recording in Reinach (taken on 08.08.2025, 12:45, BFH under the direction of Prof. Stefan Jack, ©BFH)
The key data at a glance:
- Temperature reduction on sealed surfaces by up to 32°C - Maintenance effort: 5 minutes per trough every two weeks (vs. 30 minutes twice a week for conventional systems) - Total costs over 10 years: around one-third of comparable solutions - Break-even compared to conventional systems: after a maximum of 1.5 years
How the System Works: Smart Planting Troughs Supply Trees Optimally
MobileGreen combines trees from six metres in height with intelligent planting troughs that can be positioned within hours via forklift or crane. What distinguishes the system from conventional planters starts with the water reservoir: Depending on the version, the troughs hold 400 to 800 litres. They are filled directly via a fill spout, after which the capillary irrigation runs fully automatically.
Technical image MobileGreen planting troughs (© Bauer Baumschulen)
An integrated sensor monitors water level and temperature in real-time and automatically triggers an alarm at critical values. A stabilisation system ensures the necessary stability, directly connecting the large trees to the trough without additional stakes - stable even in highly frequented public spaces.
'For us, the well-being of the plants and sustainability are paramount. With MobileGreen, we enable a long lifespan for trees and a sustainable shading solution for cities,' says Sebastian Mühlemann, MobileGreen project manager at Bauer Baumschulen AG.
From Reinach to Rotterdam: What Two Years of Practical Experience Show
In less than three years, MobileGreen has developed from a pilot project to a proven system. Today, 70 mobile trees are standing in Basel, Solothurn, Reinach, Rheinfelden, Oberwil, Burgdorf, Wohlen, and many other municipalities - even in the Netherlands.
MobileGreen trees in Wohlen (© Bauer Baumschulen)
In the Innosuisse project with the Bern University of Applied Sciences, the cooling performance of MobileGreen became clearly visible. The sophisticated system can minimise plant stress, even at extreme locations.
This has the advantage that, compared to conventional systems, large trees in MobileGreen can still evaporate water. Therefore, cooling effects beyond 32°C can be expected, making the patented system not only unique but also more deployable.
The data from the study flows into a model for calculating cooling performance (BFH, Mobile Urban Green 2). The innovative aspect of the results, expected in mid-2026, is the new possibility of pre-calculating cooling effects. Not only MobileGreen modules but also plantings can thus be easily examined for their potential without incurring high projection costs, creating a leap towards sustainable solutions with good arguments for the overheated public space.
The Solothurn location shows what the system enables in urban planning: Five large trees on the Klosterplatz can be moved by forklift as needed. The square remains multifunctionally usable for events, markets, concerts. This would not be possible with conventional plantings.
MobileGreen trees on the Klosterplatz in Solothurn (© Bauer Baumschulen)
If several troughs are arranged as a group, the shaded areas connect to form green islands. Large areas can thus be cooled step by step without structural interventions.
What This Means for Cities and Communities
The actual finding from two years of MobileGreen operation is not the temperature reduction alone, as this was to be expected. It is the combination of speed, flexibility, and cost-effectiveness. Cities no longer have to choose between greening and usage openness. Mobile green can achieve both: immediate cooling and long-term planning freedom.
'It's not about replacing tree planting with mobile green,' stresses Mühlemann, 'it's about getting greenery where plantings just can't be made.'
For more information about MobileGreen, see:
https://www.mobile-green.ch/
https://ots.ch/A0rh9t
The visual material for this release is available on the press page.
Press contact:
Inquiries & Contact
Bauer Baumschulen AG Website: www.bauer-baumschulen.ch
Sebastian Mühlemann (MobileGreen Project Manager) Email: sebastian.muehlemann@bauer-baumschulen.ch Phone: +61 405 13 37
Philipp Häfeli (Sales Field Service, MobileGreen Contact) Email: philipp.haefeli@bauer-baumschulen.ch Phone: +61 79 287 62 40