Bringing the outside in has never been more apparent, or more appealing, than with vertical gardens. And now the natural approach is growing in India too, finds out sapna kulshreshta.
Ever thought about greenery on a vertical plane? French Botanist Patrick Blanc did, and promptly turned the surreal idea into reality.
The inventor of the modern vertical gardens observed how plants were able to grow vertically without the need for soil in the wild, and soon developed a way to create artistic-looking vegetation walls that were lightweight and needed little maintenance.
The 200-metre-long and 12-metre-high exterior façade vertical garden on the Musee du quai Branly, a popular French museum in Paris, is one of the best examples of vertical gardening by artist Patrick Blanc.
Furthermore, a vertical garden, also referred to as a green wall, living wall, or sky farm, when built as a work of art for interiors, can be quite spectacular in appearance. It can even work to filter clean air into the building and help tackle the sick building syndrome.
Another advantage of soilless plant cultivation is that the plant-supporting system is very light, so it does not add any substantial weight to supporting walls regardless of size.
Pune-based landscape designer Shobha Bhopatkar says: “These amazing walls are becoming increasingly popular internationally in office buildings, hospitality and retail stores because of their outstanding beauty plus natural air purification properties.”
A blend of science and art, vertical gardens rely on the premise that soil is nothing more than a mechanical support. Thus, plants can be grown on just about any type of structure, with or without the use of soil as long as there is no shortage of nutrient-enriched water.
In fact, they can also be installed in basements and fully-enclosed spaces such as underground parking lots. In these cases, artificial lighting is required and plant selection has to be as per prevailing climatic conditions.
For instance, at Changi Airport, Singapore, the key highlight of Terminal 3 is a five-storey-high vertical garden spanning 300m across the main building. The green wall is covered with 25 species of climbing plants and is interspersed with four cascading waterfalls.
The whole organic wall display works as a visual treat for arriving passengers who are waiting for their baggage.
A living wall can either be pre-grown or planted. Landscape contractor, Anuradha Barpande of ELT India, one of the few landscaping firms to provide green wall systems in India, explains: “A modular living wall panel can be either pre-grown or planted in place. Panels are designed to be irrigated from the top by a simple soaker hose or a drip tray system.
We employ HDPE for its recyclability and long life. Its black colour also means that the plastic will be more UV stable without as many chemical additives. This plastic is resistant to chemicals found in fertilisers, ensuring a very long product life span.
The inbuilt irrigation system also ensures that root growth is restricted to the surface and leaves the walls unaffected.”
The type of soil used depends upon the type of plants chosen for the living wall, and planting is generally as per the pattern suggested by the architects or designers, she adds.
Vertical gardens can also be considered a modern form of urban gardening. They are well-suited to an urban environment, for they allow good use of vertical surface areas.
The primary cause of heat build-up in cities is the absorption and storage of solar radiation by roads and buildings, and its subsequent re-radiation.
The addition of plant surfaces as a result of transpiration enables the reduction of overall temperatures of the building, which in turn reduces energy consumption. Vertical gardens may also be a means for water reuse as the green plants purify slightly polluted water such as grey water by absorbing the dissolved nutrients.
They are suitable in arid areas too, as the circulating water on a vertical wall is less likely to evaporate than in horizontal gardens.
Though vertical gardens have been around since 1995, starting with Patrick Blanc’s ‘Vegetal Walls’, they have only recently been making a splash in India.
The ITC Royal Gardenia, Bengaluru, said to be the first hotel in India to use this concept, has vertical hanging gardens in the hotel’s main lobby and at The Cubbon Pavilion, its multi-cuisine coffee shop.
The four strips of vertical gardens at the lobby have 1,500 plants each; the one in the coffee shop reaches the second floor and has around 25,000 plants — all belonging to the Philodendron family grown locally.
The plants are divided into two layers and are watered through a state-of-the-art drip irrigation system placed at the top. “The gardens rise right up to the ceiling and bring in the mood of tropical forests to the interiors of the hotel,” says Shona Adhikari, consultant of ITC Limited Hotels Division.
Similarly, in Hotel Taj Bengal, Kolkata, designed by legendary architect Bob Fox, the magnificent 11,000 sqft atrium lobby features strikingly lit and luxuriant panels of green vertical gardens that add to its serene ambience of nature-inspired interiors.
In the same way, Spire Edge, IT Park Manesar — a proposed 1.6 million sqft eco-office complex spread across four towers with an iconic 300 ft tall mainstream green building, designed by architect Ken Yeang, features an expansive vertical garden on the building elevation which, according to AN Buildwell, the developers of the project, “reflects the ideology defining the way people will work in future.”
Residence Antilia, the new eco-building for industrialist Mukesh Ambani in Mumbai, should not be missed either. This building, scheduled to be completed by end 2010, will hold the world record for the largest and tallest living wall on the planet. This 200m tall building displays vertical gardens all the way up its exterior walls.
“You can use the whole wall like a tree and increase the green area of the site by five or 10 times over what it would be, if you did a green roof,” says Ralph Johnson, design principal of Perkins+Wills, the designers.
Worldwide, vertical gardens are a most common green oasis that can be seen in city buildings; however, in India the concept is still in its infancy due to limited awareness among clients and lack of Indian manufacturers for the green wall systems.
Landscape designer Shilpa Chandawarkar at SGC Design Group, adds: “Due to limited suppliers and contractors and high installation and maintenance costs, this innovative concept is considered by many clients as a high-end decorative feature rather than a functional energy- saving idea.”
With Indian cities turning into concrete jungles and green areas shrinking more and more, the importance of vertical gardens is gaining relevance. Vertical gardens not only ensure that the building has maximum green cover; but as the plants grow upwards, they do not require space horizontally — thereby helping to make the best use of that available area.
“What’s required is clearing of the misconceptions about its feasibility and introduction of cost-effective technology in India,” states Shobha Bhopatkar.
Indeed, vertical gardens can play an important role in any architectural situation from residential buildings to commercial projects, as they are not only space savers but also an attractive design element. They are efficient insulators, help reduce heat and noise, and act as air purifiers.
Soil-less green wall construction
A vertical garden is composed of three parts:
A metal frame: that can be fixed to a wall or is self standing. This provides an air layer which acts as an efficient thermal and phonic isolation system
A PVC layer: a 1-cm PVC sheet riveted to the metal frame brings rigidity to the whole structure and makes it waterproof.
A layer of felt: made of polyamide, it is stapled to the PVC sheet and is rot proof. Its high capillarity allows a homogeneous water distribution.
Also, plants: these are installed on the felt layer as seeds, cuttings or grown plants, and their roots grow on felt. The density requires 30 plants/sqm and the weight of the plant cum frame needs to be lower than 30 kg/sqm.
Finally, the garden can be implemented on any wall regardless of size and location, whether indoors or outdoors.
Watering needs to be done from the top and it should be packed with nutrients. This includes watering systems (water supplemented with nutrients) positioned at appropriate intervals. Collection trays at ground level allow overflow water to be discharged or recycled.
Green wall modular systems
High-strength lightweight structural panels are used that incorporate interlocking snap-on clips. It contains a geo-textile liner into which is placed a suitable planting mix. The panel has a unique grid to facilitate planting of up to 16 plants per module. The modules are pre-planted in a nursery environment to allow proper establishment.
Finally, the panels are either mechanically fastened on walls using steel bolts or inserted into free-standing structures. Modular installations include drip irrigation systems positioned at appropriate intervals, depending on the heights of the walls.