The world’s highest indoor green wall is in the new building of financial firm Desjardins in the city of Quebec, Canada. This wall, measuring 65 metres in height, is called The Currents and is designed by North-American design company Green over Grey and is inspired by the St. Lawrence River. Not only is the green wall a beautiful sight, it also cleans the indoor air and makes for a pleasant work atmosphere.


The green wall is inspired by the historical St. Lawrence River that can be seen from the Desjardins building. Mike Weinmaster, designer at Green over Grey, first observed the flow path of the river and its tributaries. Next, he spent five months working on the design for the wall and selecting the right plants for the project.

Clean indoor air

In the end, 42 plant species were selected, based on their colour, texture and size. Of these species a total number of over 11,000 individual plants hang from the wall. Together they form an impressive expression of the beauty of the St. Lawrence River. Most important is, of course, that the plants clear the indoor air. Spathyphyllum, also known as Peace Lily or White Sails, can purify toxic substances like benzene, formaldehyde and trichloroethylene. These substances are produced by copying machines, for one thing. The employees of Desjardins in Quebec, over 1,450 in number, no longer have to worry about the quality of the indoor air.

big building
The Desjardins building, with The Currents in the middle.

Planted in water

The plants are to be fixed in the wall in a very special way. They are not planted in earth but in water. This keeps the roots moist and the plants will also grow better because of the nutrients in the water. This so-called hydroponic system is completed with sustainable panels that are made of 100% recycled synthetics, such as PET bottles and plastic bags. In concept it is so beneficiary for the environment, it might receive the LEED Gold Certificate as soon as the wall is finished in September 2014. All buildings that are considered green are candidates for this American certificate.

Patrick Poiraud, co-owner of Green over Grey, is proud of ‘The Currents’. “The wall is a hydroponic systems and contains plants that grow in similar vertical conditions in nature, on tree branches or near waterfalls for example. The end result is a visually pleasing design that produces clean indoor air, improves the acoustics and increases the building’s value.”

The project contributes to Green over Grey’s mission to add more green to the grey of the city. The company has succeeded in doing so with designing green walls for Microsoft, SAP and ING Direct as well. We look forward to their next creations.