Green walls aren’t just beautiful – they may well also be one of the best solutions for urban air pollution, too
By Chere Di Boscio
Think of any city and what comes to mind? Probably an imposing, grey cement image, full of hive-like high rises with no soul. Right? Well, some architects think it’s time to change this archetypical vision – specifically through the use of lushly beautiful vertical gardens.
Also known as green walls, vertical gardens in urban areas are the brainchild of Frenchman Patrick Blanc, a botanist who took his inspiration from the waterfalls he saw in the tropical jungles of southeast Asia. His work can be seen around the world, blanketing the Genoa Aquarium in Genova, springing from the walls of the BHV Homme shop in Paris, and draped over the side of the Anthenaeum Hotel in London, for example.
Bringing cities to life
Green walls bring cities to life, and are easier to maintain than you’d imagine. They are completely self sustaining and can be incorporated into the interior or exterior walls of virtually any building. To ensure success, plants must be carefully chosen, and should include several varieties, for both visual and practical reasons: shade and moisture loving plants go at the bottom, wind and sun resistant varieties at the top, while flowering perennials, fragrant mosses and hearty evergreens can be interspersed throughout the wall, to create an Impressionistic ‘wallscape’.
Although the vast scale of green walls may make their upkeep seem daunting, automatic vertical support systems mean that very little upkeep is actually needed. Water is given through pipes at the top of the wall, which drains down to the bottom plants, which need less water. And don’t worry about the weight of the garden. In most cases, no soil is used to grow the plants at all! A layer of air between the building and the panels ensures that the building can breathe.
And speaking of breathing, these are a great solution for cleaning the air in highly polluted cities. Greenery such as spider plants, English ivy and peace lillies have been proven by NASA to be especially advantageous when it comes to cleaning the air.
This layer of air can provide insulation for homes, making green walls not only beautiful, but practical too. According to Nick Miles of the energy company The Green Age, “Most of the focus on insulating homes has been to insulate from the inside, especially insulating floors and roof space, but green walling offers an external solution too: the layer of air that it creates reduces the amount of heat escaping from the building, and the amount of cold air that comes in.”
Miles says there are even further energy benefits to green walls: “There are energy savings in the summer too – through the process known as transpiration, plants actually slightly cool the environment around them, and a large green wall with a variety of plants can reduce the temperature of a room in summer significantly.”
Beautiful and practical, green and gorgeous, vertical gardens have the potential to not only reduce energy consumption, but to transform cities from dull, depressing concrete jungles into living, thriving gardens of urban Eden. We sincerely hope more construction companies, home owners and city councils decide to incorporate them into the urban landscape!