Source: Greenwall

Whenever I go to look at comments as to why humans feel less stress when they have access to green areas – parks, forests, gardens – I come across a multiplicity of suggestions. We like the color green because it represents harmony and trust to us; green spaces encourage social contact and thus a healthier interaction between individuals; access to green spaces usually indicates a certain level of safety in a neighborhood or area, and people are more likely to walk outside and get some exercise.

Why do we feel better in the presence of plants and trees and green than we do without them? Maybe we’re just like any other creature – the presence of greenery means the presence of life.

Musée du Quai Branly, Paris, France
Source: GreenRoofsAustralasia

This might explain why work productivity seems to go up in buildings with green walls. This article describes five reasons people work better in green buildings. Air filtration, temperature regulation and a reduction in noise pollution can be attributed to a higher degree of comfort.

But the other two reasons, visual aesthetics and improved vision, are a different matter. Green walls are soothing, they change color over the course of the days and seasons, they are in constant movement, unlike static concrete and glass.

We humans came out of the trees and forests a long time ago, but the human eye remains more sensitive to light wavelengths associated with green and can pick out far more shades of green than any other color. Green is our friend.

Maybe green walls have a deeper effect on us. Perhaps they awaken an ancient nostalgia.

Maybe they still carry the comfort of what was once home.

Studio, San Francisco, USA
Source: John Sutton Photography via Treehugger