The Federal Council wants to fight against gardens covered with stones – rts.ch
Covering your garden with slabs or gravel is a growing trend in Switzerland. However, these developments reduce biodiversity and create heat islands. A report recently adopted by the Federal Council makes several recommendations to combat these developments.
They are called stone gardens and we see them spreading everywhere: on the grounds of individuals, businesses or even schoolyards.
These areas increased by 21% between 2018 and 2021, reaching a total area of around 11 km2, according to an estimate by the Federal Office for the Environment (FOEN).
If they are so successful, it is because they are often easier to maintain than a traditional garden, with a lawn to mow, plants to trim or weeds to pull out.
Impact on biodiversity and local climate
These stones are generally installed on a separation layer such as a fabric, a plastic film or even concrete, which suffocates the fauna and flora.
But that’s not all.explains that, under the sun, stones can reach temperatures of over 50 degrees, creating heat islands.
“The gravelling will not change the general climate. On the other hand, it has an impact on the climate of the city and on the feeling of heat experienced during episodes of high temperatures and drought in the summer”, explains Edward Mitchell , professor of biology at the University of Neuchâtel. He specifies: “The more the environment is concreted, the less the regulation of the climate can be done by the water of the ground and by the vegetation.”
>> Edward Mitchell’s clarification:
Furthermore, the FOEN also notes the acceleration of surface runoff, with water that is no longer absorbed by the ground. A particularly problematic phenomenon during heavy rainfall.
Towards better regulation
To fight against the encroachment, the report of the federal office of the environment proposes three recommendations. The first concerns the establishment of binding rules at municipal level. The stone gardens would thus be subject to building permits.
The Federal Council also supports the idea of financial aid to develop green spaces in the city, with the planting of trees or the erection of green facades.
The third solution involves awareness campaigns aimed at the authorities and the population.
It should be noted that some municipalities did not wait for these recommendations to act. This is the case of Langendorf, in the canton of Solothurn, which has banned any new stone gardens since 2020.
The FOEN specifies that projects to further regulate these areas are also under discussion in several French-speaking cantons, including Fribourg, Valais and Vaud.