Vertical gardens are nowadays very common in our cities, where this peculiar treatment for walls is used both on public building façades and for private property projects.
Since Parisian botanist Patrick Blanc came up with the idea, vertical gardens have come a long way, from the first famous creation on the façade of the Quai Branly Museum to the most recent indoor installations.
The green façade of the Quai Branly Museum
How does a green wall work?
A vertical garden, also known as green wall, is a composition of different plants placed on a vertical structure, fixed onto the building wall.
The plants, usually chosen depending on the climate and the sun exposure of the wall on which they are to be placed, grow on felt and PVC multilayer panels. This way, it’s possible to make the most of hydroponic techniques. These panels are inserted into a metal grid, placed slightly detached from the building wall, in order to guarantee proper ventilation and waterproofing.
This kind of farming enables constant rainwater and fertilizer supplies, through an irrigation system placed at the top of the green wall.
Another solid and efficient method for the growth of the plants is a structure with basins where each row has its own irrigation system.
The positioning of the different plants that constitute the vertical garden must necessarily take into account the local microclimatic conditions, which also vary depending on the wall’s height, especially for outdoor vertical gardens.
Also, you mustn’t forget about the importance of the aesthetic effect, therefore the positioning of the different plant species will also depend on the colours and the “pattern” you want to get when the work is done.
Different-coloured plants
Vertical gardens: what are the benefits?
The spread of the use of green walls, both indoors and outdoors, is not just because they are aesthetically pleasing, but also because of the clear need to improve a building’s climatic features, both inside and outside.
More precisely, a wall with a vertical garden has not only a great aesthetic effect, but also a climate control function. Vertical gardens in fact improve air quality, both inside and outside of buildings. Plants, as you will know, automatically filter air, absorb toxic chemicals and suppress dusts.
Green walls are also highly sound insulating, which is very helpful in cities as a vertical garden can reduce sounds up to 40 Decibels. Installing a green wall is therefore an effective method for lowering noise levels inside of buildings.
How is an indoor green wall made?
Similarly, vertical gardens installed inside of buildings lend a great personality to the rooms and make beautiful backdrops for both work environments and private residences.
Since the plants are going to stay inside a building, when planning the vertical garden it is necessary to choose plants that best adapt to living indoors.
An example of indoor vertical garden
It’s important to properly illuminate green walls since, depending on their planimetric position, it’s fundamental to combinr natural light with artificial lighting to make sure that the plants have a sufficient light intake.
For this kind of green walls, plant irrigation, through a specific irrigation system placed in conjunction with the supporting structure, is necessary since rainwater wouldn’t be enough.
There are two different types of irrigation systems for indoor vertical gardens:
– the open-loop system includes water supply and drain so that the vertical garden is completely autonomous. The irrigation is managed by a control unit;
– the closed-loop system includes a water storage tank that autonomously waters the plants. In this case, it’s necessary to remember to fill the tank before the water storage runs out.
An equally fascinating alternative for using indoor green walls is the possibility of installing free standing structures with vertical gardens on both sides, that can also work as partition in private or business spaces.
Speaking of installing indoor green walls, green paintings are also a beautiful and greatly evocative alternative. Green paintings are a variation of green walls that allow plants to become a designer element even in narrow spaces.
Are all green walls the same?
Vertical gardens are obviously not all the same. There are in fact different building technologies, just like for the other elements in a building. The most common techniques are:
– the hydroponic wall, that is a vertical garden grown with hydroponic farming (in which plants don’t need soil to grow). In this case, pouches for plants are made on the building’s “green skin”. This skin is waterproof and therefore blocks the sunrays, so the plants absorb nutrients dissolved in water from an inert underlayer.
– the green wall, the technique developed by Patrick Blanc, in which the plants are placed on self-supporting mats, with an irrigation system installed on the whole surface. The result is a thick drape, about 20 to 30 plants per square metre. The felt panelling works both as support and as water storage for the plants.
Vertical gardens: what about maintenance?
Maintenance frequency for these peculiar “vertical green walls” depends on the plants chosen and can range from one to four times a year, while for indoor green walls maintenance must be more frequent.
In this case, especially when walls are installed in private residences, it’s important to choose plants that don’t have an excessive growth, to avoid that they “invade” the room.
Because of the beauty and versatility of plants, the technology for plant growth on vertical surfaces can be applied practically anywhere, from the large façades of public buildings to small squares skilfully inserted on a private residence’s wall.
Here lies the magic and the popularity of vertical gardens: having the possibility to own, independently from the space available, a personal green spot.
Nizza Paradise, a wonderful vertical garden
An emblematic example of vertical garden was created by our firm, Mino Caggiula Architects.
The green wall of a residential building
You can admire this “green work of art” inside the Nizza Paradise Residence, a luxury residence located in Paradiso (Lugano, Switzerland).
Find out more at nizzaparadise.ch.