Finland’s Largest Outdoor Green Wall: Reflections After the First Summer

Testing a wide variety of plant species

Although the plants were lifted into place in May, they had already been planted in growing containers in the fall of 2024. This early planting allowed the roots to establish well before installation, ensuring a quick start to growth in the spring. Over the summer, the wall became greener week by week. The change was most striking in the climbing plants: clematis and honeysuckle that were less than half a meter tall in spring have now grown several meters, spreading beautifully across the structure.

The performance of different plant species has been carefully monitored. Shrubs such as European hazel and ninebark have thrived, while the climbers have shown surprisingly strong growth. However, not all species proved suitable. For example, the Tornio Valley rose did not survive the winter. Those that struggled have been replaced with species better adapted to the wall’s conditions.

The summer also put the irrigation system to the test, a system that runs entirely on locally collected stormwater. During heavy rains, water is stored in tanks to ensure sufficient supply during dry periods. The July heatwave challenged the system, but the irrigation worked as planned and the vegetation remained healthy.

“It was encouraging to see the system perform well even during an exceptionally hot summer. This proves that nature-based solutions can provide truly functional structures in urban environments,” says Amanda Tala from InnoGreen’s landscaping team.

Maintenance follows the rhythm of the seasons

The green wall has caught the eye of many passersby. Most people are surprised to learn that the plants are real and remain in place year-round. Since no similar wall has been built in Finland before, both the structure and the vegetation have drawn a lot of curiosity.

Because the wall is made of living plants, professional maintenance is an integral part of the concept. Growing conditions differ from those at ground level, so continuous monitoring has been crucial from the start. Some plants were quickly found unsuitable and were replaced early on. Once the right species were identified, maintenance efforts focused on managing growth.

During maintenance, the plants are guided and pruned as needed to ensure the wall grows naturally yet remains balanced. Decisions about trimming or controlling certain species are always made case by case to keep the wall lush and harmonious. Maintenance takes place every 2–4 weeks using a lift that raises gardeners up to 16 meters. Overall, both maintenance and irrigation have operated smoothly, with no major issues.

As fall approaches, the irrigation system is gradually shut down, and the plants prepare for winter. Seeds and berries from perennials and shrubs provide food for birds, while the leafless forms give the wall a distinct winter appearance.

“Maintaining the wall has been a new and educational experience. It’s wonderful to see how it transforms and reflects the rhythm of the seasons,” says Amanda Tala.

She adds that the main focus in spring will be seeing how well the plants have overwintered. “We’ll document and record the condition of the vegetation. Once the plants are fully rooted and adapted to their environment, we expect the wall to grow even greener and more vibrant next summer.”

Read more about the Vertical Garden here.

The project partners include InnoGreen, Turun Teknologiakiinteistöt, architect Joonas Parviainen and Studio MANA, structural engineer Asko Keronen, HVAC designer Tero Lind, TopCon Oy, and Rakennustoimisto Lundén Oy (Lundén Construction).