Temporary Greenery Takes Over Helsinki: Seven Experiments Begin

Cities are seeking new ways to increase vegetation and support biodiversity even in densely built environments. Previously, Helsinki has experimented with temporary green oases, communal gardening, and tram stops covered with plants. This summer, the PilotGreen project, co-funded by the European Union, which invests in innovative green solutions, brings seven experiments to Helsinki. These will green a metro station, Ilmalantori square, and a daycare center, as well as support green area maintenance, children’s connection to nature, and the measurement of the effects of temporary plantings.

Experiments in Helsinki in Summer 2025

Vertical Greenery at Herttoniemi Metro Station

This experiment involves creating a green wall structure where a growth medium mixture containing seeds is sprayed onto a pre-fabricated green wall element. The pilot will investigate plant species suitable for domestic green walls and develop a growth medium mixture, considering the possibilities of using recycled materials. This experiment is backed by Rakennusbetoni- ja Elementti Oy and Sitowise Oy.

Reusing Glued Laminated Timber Rescued from Demolition

The Ekokatos (Eco-shelter) is a bus stop that will be placed outside Herttoniemi metro station, protecting bus-waiters from rain and heat. In line with the circular economy, the glued laminated timber used for the stop’s construction will come from a demolition site. The stop’s roof will feature plantings, and its sloping shape will direct rainwater into the structure, acting as a passive irrigation system. Spolia Design is responsible for this experiment.

An Oasis in Ilmala through Corporate Collaboration

Ilmalantori, an empty square in Ilmala, will be greened as local company employees collaboratively build an oasis there. In this project, led by Sweco, temporary green furniture and planters will be filled with wild plants and flowers rescued from construction sites. Several new solutions will be tested in the square throughout the summer. Businesses in the area will also organize programs on-site.

You can read more about the Ilmala oasis in the news article on the topic.

Pollinator Roof at the Metro Station

This summer, the roof of the Herttoniemi metro station entrance will feature a meadow, wildflowers, and bumblebee nests. The 30-square-meter meadow area will provide food and resting places for pollinator insects in the neighborhood. eDNA analysis of pollen collected by bumblebees will provide information on the biodiversity of the surrounding nature. A similar meadow solution was successfully trialed last summer on the Sokos canopy in Tampere. The Herttoniemi experiment is being carried out by Blokgarden and HumbleBee Housing Project.

Satellite Data to Support Green Area Maintenance

Helsinki is experimenting this summer with how satellite data can be applied to the maintenance of urban green areas. In this experiment, Lensor, a company specializing in utilizing space technology, and Viherpalvelut Hyvönen, a green services provider, are investigating whether satellite data can reduce unnecessary field visits, optimize mowing times, and improve fertilizer use. Ideally, the results will aid both decision-making and land use planning.

Data Reveals the Significance of Temporary Greening

Helsinki has experimented with various temporary plantings and greening initiatives, but there is still relatively little information about their benefits. Plantings will be implemented in Kallio for the summer, and their significance for the city’s biodiversity will be measured using eDNA technology. This technology can measure how adding plants and soil to a built environment affects bacterial diversity. This biodiversity has been found to be linked to human health. The experiment is being conducted by SpringDNA.

A Summer of Growth in Daycares and Schools

The Summer of Growth experiment will bring green structures to the yards of four Helsinki schools, pre-schools, and daycares, where children and parents can care for and observe the plants. The idea is that children will be able to interact with nature in the future, and the plantings will connect the pre-school and school yards of incoming first graders into a cohesive, familiar whole, lowering the threshold for transitioning to first grade and promoting education for sustainable development. At the same time, the biodiversity of the yards will increase. This experiment is backed by Ympäristökoulu Polku.