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Advances in Floriculture and
Landscaping Gardening
Volume-3
Chief Editor
Dr. Eerati Sathyanarayana
Department of Floriculture & Landscape Architecture, School of Agricultural
Sciences, Malla Reddy University, Hyderabad, Telangana
59
Chapter-3
Sudha Patil
Tejal Patel
S. L. Chawla
Dipal S. Bhatt
M. A. Patel
60
61
Chapter-3
Sudha Patil, Tejal Patel, S. L. Chawla, Dipal S. Bhatt and M. A. Patel
Abstract
The lack of vegetation in urbanized areas, as a result of human establishments,
directly affects the quality of life, from physical and aesthetical point of view. The
construction of vertical gardens is recommended both in interiors and especially in the
exterior of buildings. By applying these technologies, any kind of area can be used at
its maximum capacity, obtaining aesthetic valences, benefice for environment and
human health. The new modern concepts for landscape development are keen on using
any kind of concrete or glass, turning them in real vertical gardens, being possible to
overcome the development of the urban areas making a smooth transition for a healthy
green urban environment. Vertical Gardening is a special kind of urban gardening
suitable to small spaces, particularly for decorating the walls and roofs in various styles.
This is an alternative method for gardening by expanding the scope of growing plants
in a vertical space. Intensive urbanization has left hardly any horizontal space for
outdoor gardens. Green walls in indoor and outdoor are not only spectacularly beautiful,
but also helpful in enlivening the ambiance. Green walls can absorb heated gas in the
air, lower both indoor and outdoor temperature, providing a healthier indoor air quality
as well as a more beautiful space.
Key words: vertical garden, landscape, urban gardening, green walls
Introduction
Green Wall with another name Vertical Garden is the term used to refer to all
forms of vegetated wall surfaces (Anonymous, 2008). Vertical gardening is an
innovative, effortless and highly productive growing system that uses bottom-up and
top-down supports for a wide variety of plants in both small and large garden spaces.
Vegetables, fruits and flowers come in hundreds of kinds and are ideal for different
purposes like growing in beds or containers, on wall-mounted or freestanding supports.
Not only do green walls have amazing aesthetic value, but they also contribute to a
lively atmosphere. Green walls can absorb heated gas in the air, lower indoor and
outdoor temperature, providing healthier indoor air quality and a more beautiful space
(Yeh, 2012). They hold or slow down the run off of rainwater along with providing food
and shelter for wildlife (Thompson and Sorvig, 2000). Certain plants can grow on walls
by establishing roots in the wall's material, as was previously explained. The little
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herbaceous species like wallflowers, mosses, lichens and grasses, as well as ivy-leaved
toadflax, are typical examples of these. However, some species have evolved naturally
to climb up and over barriers like trees, plants and rock faces. Generally, some sort of
support system is necessary for them to grow properly on walls and buildings (Johnson
and Newton, 2004). Furthermore, a variety of techniques can be used to build green
walls.
Brief History of Vertical Garden
Around 2500 years ago, the concept of Green Walls was constructed in
Babylon. A historical wonder and the forerunner of the contemporary green wall, the
Hanging Gardens of Babylon were constructed by King Nebuchadnezzar II of Babylon.
Romans trained grapes between the 3rd BC and 17th AD on garden trellises and
villa walls.
In the 1920s, Britain and North America promoted trellis structures and self-
climbing plants on houses and gardens.
In early 1990, cable and wire-rope net systems and modular trellis panel
systems entered the North American marketplace.
The first major application of a trellis panel system was used in Universal City
Walk in California in 1993 and 1994. Indoor living wall with biofiltration system
installed in Canada Life Building in Toronto.
Types of Vertical Garden
Green walls can be divided into two main groups: living walls and green
facades. These groups can be further subdivided into groups (Fig. 1). Climbing plants
are the main component of green façades; they can grow right up to a wall or in specially
created supporting frameworks. With its roots in the ground, the plant shoot system
Fig. 1: Types of Vertical Garden
Garden
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climbs the side of the structure. Conversely, the modular panels of a living wall often
consist of plants, irrigation systems, growing media, geotextiles, and polypropylene
plastic containers (Sharp, 2007 and Anonymous, 2008).
1. Green facades
Green facades are a type of green wall system in which climbing plants or
cascading vegetation can be anchored to existing walls or built as freestanding
structures, such as fences or columns (Anonymous, 2008 and Gonchar, 2009).
Three green facade systems which are frequently used are Modular Trellis Panels, Grid
System and Wire–Rope Net System (Yeh 2012).
1.1 Modular trellis panel system
This modular system's fundamental component is a three-dimensional, stiff,
lightweight panel supported by plants with a face grid and panel depth. It is constructed
from powder-coated, galvanized, and welded steel wire. This technique offers a
"captive" growing environment for the plant with several supports for the tendrils, keeps
a green façade off the wall surface so that plant components do not stick to the building,
and aids in maintaining the integrity of a building membrane. The panels are recyclable
and composed of steel with recycled content. They may be stacked and combined to
cover vast surfaces or shaped to create patterns and curves (Fig. 2 and Fig. 3). The stiff
panels allow them to span across buildings and can be utilized on their green walls
(Anonymous, 2008).
Fig. 2: Freestanding trellis fence (left), coloumn trellis (centre), custom trellis
shapes (right)
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1.2 Grid and wire-rope net systems
Cables and wires were employed in the planning of the Grid and wire-rope net systems
(Fig. 4 and Fig. 5). Grids are used on green facades that are intended to hold climbing
plants with denser foliage that grows more quickly. Wire-net systems are frequently
employed to support slower-growing plants that require the extra assistance that these
systems offer. High-tensile steel cables, anchors and additional hardware are used in
both systems. Because flexible vertical and horizontal wire ropes are joined by cross
clamps, a variety of sizes and patterns can be accommodated.
Fig. 3: Modular wall hung trellis (left), Installation of trellis (centre), curved
trellis (right)
Fig. 4: Grid System, Ex Ducati Office, Italy
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2. Living walls
Vertical gardens or bio-walls are other names for living walls. Pre-vegetated panels,
vertical modules, or planted blankets make up living wall systems. These panels, which
sustain a wide variety and density of plant species, can be constructed from plastic,
expanded polystyrene, synthetic fabric, clay, metal, and concrete. The variety and
quantity of vegetation on living walls require greater care than that of green facades.
Living Walls consist of three layers: a PVC layer, an air layer (which doesn't require
soil), and a metal frame. This system can withstand a range of plant species, including
low shrubs, ferns, perennial flowers and a mixture of vegetation (Fig. 6). It also adapts
well to different climatic conditions however, the selection of better species may require
so that the maintenance of the system can be made easy. Generally, self-automated
watering and nutrition systems, make maintenance of the living walls easy.
Fig. 5: Grid and Wire-Rope Net Systems, MFO Park, Switzerland
Fig. 6: Living wall of Semiahmoo Library, South Surrey
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2.1 Landscape walls
This wall system is a development of landscape 'berms' and a tactical aid in the practice
of 'living' architecture. The main purposes of landscape walls, which are usually sloped
rather than vertical, are slope stabilization and reduction of noise (Fig. 7). Typically,
they are constructed using concrete or plastic stacking materials that have space for
plants and growing media.
2.2 Vegetated mat walls
Patrick Blanc invented a novel type of green wall known as the "Mur Vegetal" (Fig. 8).
It is made up of two synthetic fabric layers with pockets to hold plants and growing
medium in place. Because of the building wall's high moisture content, the fabric walls
are backed by a waterproof membrane and supported by a frame. According to the Gren
Roof Organization (2008), the main method of distributing nutrients is through an
irrigation system that cycles water from the top of the system down.
Fig. 7: Landscape Walls
Fig. 8: Vegetated Mat Walls, Madrid, Spain
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2.3 Modular living walls
With several technological advancements, a modular living wall system was partly
inspired by the usage of modules for green roof applications. Square or rectangular
panels that contain growing media to support plant material make up modular systems
(Fig. 9).
Benefits of vertical gardening
Vertical Gardens provide economic and ecologic benefits as well as aesthetic value. The
benefits change with options such as different buildings, green wall technologies, plant
selections and plant coverage. This part examines important values of Green Walls.
1. Beauty abounds and adds visual drama
One of the quickest and most economical ways to improve a building's public image,
erase unfavorable opinions of the neighborhood, and dramatically improve the city's
social, economic and
aesthetic conditions is
through the use of plants (Fig.
10). According to research,
adding vertical gardens to
buildings can significantly
boost their amenities and
garner public recognition,
turning them into identifiable
landmarks and ultimately
raising property values
(Anonymous, 2013).
Fig. 9: Modular Living Wall Canada (left), Atlanta Botanical Garden (right)
Fig. 10: Quai Branly Museum
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2. Covers up views of plain or ugly walls and provide building protection
It helps in giving live look to plain dead concrete wall of the building. It also reducing
temperature within the building envelope is the primary method of producing
building protection (Fig. 11). Reduced temperature swings lengthen the building's
lifespan by minimizing the expansion and contraction of the building's materials. By
decreasing the carbonization and cracking of the building envelope, green walls
protect the building against ultraviolet light and acid rain, increasing the building's
longevity (Doernach, 1979).
3. Decrease voice level
Plants and soil utilized in vertical garden arrangements can absorb sounds. Because
of this, they take steps to reduce voice function, which is observed in the building
and its surrounding region (Fig. 12). Green walls act as a buffer against outside noise,
reducing vibration and noise levels up to 40dB inside our homes and offices. An
enclosed office surrounded by a tiny indoor shrubbery will cut noise levels by five
decibels. (Erdogan and Khabbazi, 2013 and Wong et al., 2010).
Fig. 11: Bridge in France
Fig. 12: Living Wall for voice level
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4. Conserves water and watering takes less effort
Water management is one of the main advantages of vertical gardens. To begin with,
watering is quite effective since it may be done with a hydroponic or drip irrigation
system. Any leftover water is gathered in a special tray at the base of the garden and
drained out. Or, it might be recycled and repurposed for the landscape. This indicates
that there is very little waste and that the plants essentially use up all of the water.
Additionally, since runoff does not enter stormwater systems, pollutants present in
stormwater or waste water do not damage natural rivers.
5. Reduces CO2 levels and increases oxygen and improves air quality
By eliminating current greenhouse gas emissions and other volatile organic
compounds from our contaminated cities, a Greenwall provides immediate
environmental benefits. Through a variety of biochemical processes, plants function
as bio-purifiers and can significantly enhance the quality of urban air by eliminating
and decomposing airborne pollutants from both inside and outside of buildings.
Using living plants as bio-purifiers in contaminated metropolitan areas makes sense
when you consider that photosynthesis in plants creates clean, oxygen-rich air. The
air in an office space measuring 100 square feet can be filtered by one square foot of
vegetated wall. In general, according to Erdogan and Aliasghari Khabbazi (2013),
planting one wall of any home that has 50 dwellings on the street is equivalent to
planting 50 trees on this street as vertical gardens have ability to enhance the indoor
and outdoor air quality in built-up environments. This is due to the fact that plants
act as natural filters, extracting carbon dioxide from the atmosphere and substituting
it with vital oxygen. This indicates that the air you breathe is far healthier and
cleaner. Research has demonstrated that the vicinity of a living wall has far lower
levels of pollutants.
6. Prevent from dust and harmful microorganisms
With their roots and leaves, plants generate moist habitats that lower wind speed and
avoid dust. Using this occurrence, plants eradicate dangerous germs through their
sap and juice. Plants can increase air quality by thirty percent, and twenty-four
percent reduction in coughs and dry throats. Additionally, by absorbing pollutants
into their leaves and passing the toxins to their roots, where they are converted into
plant food, the plants purify the air in the office. Building occupants are less likely
to become ill when the air is cleaner, and rooms with plants have 50% to 60% less
airborne mold and germs than rooms without plants (Wolf 2002).
7. Acts as natural insulation for hot and cold air and saves energy for building
By keeping the city cool, living walls indirectly lower the need air conditioning and
thus, the energy used by urban buildings can be reduced. In the summer, vegetation
on walls can help cool buildings, and in the winter, it can help with insulation.
Evergreen trees provide some insulation during the winter months by keeping a layer
of air against the facade and minimizing convectional heat loss. Up to 30% of an
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insulating effect has been seen; nevertheless, a high percentage like this is most
likely to occur when temperatures are close to freezing. When it comes to well-
insulated structures, such as those with brick cavity walls, energy savings are less
noticeable. Building temperatures rise in the summer due to heated walls, which puts
extra strain on cooling systems and increases energy consumption. When a green
wall is covered with plants, the surface temperature of the wall drops, lowering the
building's cooling load. Green walls have the potential to lower wall temperatures
by up to 15°F, which can save a lot of money on air conditioning (Johnston and
Newton, 2004).
The Tokyo Institute of Technology found that Green Wall panels lower down the
wall temperatures by 10°C in the walls which were taken for testing. Additionally,
it was found that green wall panels lessen the amount of energy that enters a building
by about 0.24 kWh/m2. The computation of energy savings from green walls is
highly dependent on various parameters, including the wall's orientation and the
angle of the sun.
8. Plants are less accessible to diseases and pests
Many pests are unable to reach the plants because of their vertical growth. This
indicates that there is no frequent attack of pests on plants grown in vertical garden,
which eliminates the need for chemical pesticides and insecticides. Additionally, the
vertical garden receives plenty of sunlight and good air circulation, which reduces
the likelihood of mildew, fungus and other pathogens developing in the plants.
9. Live plants decrease stress levels, create a peaceful ambiance
The regenerative power of natural landscape has been shown in vertical gardens,
where it can focus viewers' attention, distract them from negative thoughts and
oneself, and induce a meditative-like state. By offering a physical and spiritual
connection to nature, they lessen the physiological and psychological strains of city
living. The visual appeal of a
green wall that covers steel and
concrete can revitalize our spirits
and significantly lessen physical
exhaustion. Having plants in the
office helps employees be more
productive while also reducing
stress. Participants of the Texas
A&M University and Surrey
University study also reported
feeling more attentive when
plants were present (Fig. 13).
Participants who worked in an environment with plants were 12% more productive
and less stressed than those who worked in an environment with no plants.
Fig. 13: Living walls at Gutman Library
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10. Increases value of home or office building
Plants are among the quickest and most affordable ways to improve public
perceptions of a location, raise a building's image, and dramatically improve the
city's social, economic, and visual amenities (Fig. 14). It has been demonstrated that
the use of vertical gardens raises property values by significantly enhancing building
amenities and garnering greater public recognition, turning them into identifiable
landmarks. According to American and British studies, having a green plant can add
the value of a property between 6 and 15%.
11. Help restore the places where wildlife can survive
Today, habitat loss is the biggest hazard to wildlife since natural habitats are
disappearing at an alarming rate. One way to aid in the restoration of wildlife habitats
is with green walls. A Green Wall will draw birds and butterflies if appealing plant
species are thoughtfully chosen and planted (Fig. 15). It is possible to create green walls
that will give butterflies, bees and birds the best possible habitat. According to Johnston
and Newton (2004), it can offer areas to bear and raise children as well as water, food
sources and protection. The installation of an outdoor living wall has additional
advantages. They aid in reducing the effects of the urban heat island.
An urban heat island (UHI) is a metropolitan area that experiences notably
higher temperatures than the surrounding rural area, particularly during the summer
months during the late afternoons and evenings. To distinguish this effect from global
warming, scientists refer to it as the "Urban Heat Island Effect. "The Heat Island Effect
can be explained by several factors, but increased urbanization is the primary one. By
far the most common method for keeping the city cool is using green walls. By
absorbing a large amount of heat through evaporation, green walls help cool buildings
and significantly lessen the impact of the heat island effect (Yeh, 2012).
Fig. 14: BHV Homme in Paris (left); Pacha, The Driver, London (right)
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Some of the suitable plants for vertical gardens
A lot of plant species can be used for Vertical Gardens. For example, there are
15000 plants from nearly 150 different species are collected by the Caixa Forum
Museum vertical garden which was designed by Patrick Blank. In this case, it is
impossible to give all the plants but some plants which can be used for different types
of vertical gardens are as below.
Green Façades: Hedera helix, Parthenocissus spp, Hydrangea petiolaris, Polygonum
bauldschianicum, Lonicera spp. Clematis spp. Aristolochia spp. Jasminum
officinale, Passiflora caerulea, etc.
Living Wall: Dracaena, Phalaenopsis spp, Asparagus sprengeri, Kalanchoe, Cordyline
spp. Chlorophytum spp., Haworthia spp., Tradescantia sp, Fittonia spp,
Nephrolepsis, Clematis, Gardenia spp., Asplenium nidus, Maranta spp.,
Cotoneaster, Euonymus fortune, Hedera helix, Hydrangea, Lonicera,
Parthenocissus, Polygonum, Pyracantha, Selaginella, Wisteria, Rose, Petunia,
Nasturtiums, Daisies, Bromeliads and even some vegetables like tomato, chillies,
cucumber, peas lettuce, etc.
Exterior Wall: Lavendula, Portulaca, Thymus, Rosmarinus or Salvia for full sunlight
while Begonia, Arum, Davallia, Asplenium, and Fuchsia for shady locations.
Interior Wall: Philodendron, Epipremnum, Aeschynanthus, Columnea, Saintpaulia,
Begonia or different ferns like Nephrolepis, Pterisandmany, some species of
Pepromia, etc.
Fig. 15: Guggenheim Museum, Bilbao, Spain
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References
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