Horticulture
Horticulture :: Landscaping :: Vertical Gardening

VERTICAL GARDENING

Introduction:

The lack of vegetation in urbanized areas, as 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 esthetic valences, benefic for environment and human health. Even if the price of constructing and maintaining the vertical gardens is higher than a classical landscape it’s compensated by the environmental benefits, raising the vegetation surfaces, with impact for reducing the pollution effect. 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   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.

Types of vertical greening system:

1.Green façade

2.Living/green wall

     
 i) Modular green walls

      ii)Vegetated mat wall

  

Green facades:

  • Green facades are a type of green wall system in which climbing plants or cascading groundcovers are trained to cover specially designed supporting structures.
  • Plants are either grown in the ground or in the elevated containers where they are watered and fertilized

Green facades are a type of green wall system in which climbing plants or cascading groundcovers are trained to cover specially designed supporing structures. Rooted at the base of these structure, in the ground, in intermediate planters or even on achieving full coverage. Green facades can be anchored to existing walls or built as freestanding structure, such as fences or columns

Green walls / Living walls :

Living wall system composed of pre-vegetated panels, vertical modules or planted blankets that are fixed vertically to a structural wall or frame. These panels can be made of plastic, expanded polystyrene, synthetic fabric and support a great diversity of plants species ( eg: a lush mixture of ferns, ground covers, perennials and edible plants).
Constructed from pre-vegetated panels, vertical modules or planted blankets (vegetated mat wall) that are fixed to structural framework or to a wall Made from steel framework, plastic, expanded polystyrene and synthetic fabric to support a variety of diversity and density of plant species Tend to require more maintenance such as fertilizer and water than green facade systems that are planted into the ground

Modular green wall : Vertical Garden Modules is made up of recycled poly propylene material. It has attractive look, highly durable in nature and it can be easily installed. It provides instant solution for making garden in your residing place.

Green wall cups:

  • Frame/ Supporting panel
  • Easily detachable cups/pots

Green wall cup type/ Biowall cups

Vegetated mat wall :

          This system, pioneered by Patrick Blanc, is composed of two layers of synthetic fabric with pockets filled with the plants and growing media .The fabric walls are supported on a framework  and backed by a waterproof membrane against the building wall Nutrients and water are delivered through an irrigation system at the top of the wall

Building and installation of Green walls:

Green wall system vary greatly in their design and construction from DIY projects to modular green wall systems. This heading provides information on

    • Structures and components for green wall system
    • Suitable Plants
    • Growing media
    • Iirrigation and plant nutrition
    • General considerations for green walls

Structures and components for green wall system:

  • Front panel
  • Bottom drainage tray
  • Geo textile pouch
  • Stabilizers
  • Side panel
  • Hanging hook

 

Front panel Side panel Stabilizers Bottom drainage tray Completed module

Choosing the plants :

The best plants for vertical gardens are dense, compact and low growing. Make sure you choose species that suit the aspect of the wall on which they’ll be growing. A wall drenched in sun, for instance, will need a selection of fairly drought-tolerant plants, whereas a shady spot – perhaps under a pergola or verandah – will require a selection of shade lovers, such as ferns. Also bear in mind that the bottom of the unit will hold more moisture than the top, so consider this when you’re deciding what to plant where.
Apart from aesthetic preferences and the plants ability to grow in a soilless, vertical location; the selection of plants is based on several factors, for example: What is the local climate like (minimum temperature especially important to know)? How much sun exposure is each area of the surface receiving and how does it change during the year? Is there any particular micro climate — such as high buildings creating strong winds along a wall? Understanding the prevailing growing conditions is essential to make the right decision when choosing plants.

Plants suitable for vertical garden :     

Outdoor plants Peperomia, Syngoniums, Philodendron, Epipremnum, Begonia, Anthuriums, Nephrolepis, Chlorophytum, Lantana, Pilea, Rheo discolor, Cuphea, Fittonia, Spathiphylum, Schefflera

Indoor Green walls/ For shaded areas:

Herbaceous perennials Pepromia, Syngoniums, Philodendron, Epipremnum, Pepromia, Begonia, Anthuriums, Chlorophytum, Pilea, Rheo discolor, Fittonia, Spathiphylum, Schefflera
Shrubs Schefflera, Ficusspp
succulents Rheo discolor, Zebrinapendula, Setcreaseapurpurea
Ferns Nephrolepis

For Outdoors/Exterior Green walls:

Herbaceous perennials Asparagus spp., Pileamicrophylla, Alternenthera, Mentha spp.
Succulents Jade plant, Sedums, Portuluca
Shrubs Dusty miller, Cuphea
Ground covers Baby’s tear, Callisarepens
Grass like foliage forms Ophiophogon, Dianellatasmanica

Growing media:

Requirements:

  1. Weightless media
  2. High Water holding capacity
  3. High Nutrient holding capacity
  4. Good Porosity
  5. Neutral pH

Cocopeat, Perlite, Sphagnum moss, vermiculite, vermicompost, shredded bark and leaf molds are the common media combinations used. Soil in not used since it increases the weight of the green walls.

There are three types of growth media used in living walls:

  • Loose media
  • Mat media
  • Structural media.

Loose medium walls tend to be "soil-on-a-shelf" or "soil-in-a-bag" type systems. Loose medium systems have their soil packed into a shelf or bag and then are installed onto the wall. These systems require their media to be replaced at least once a year on exteriors and approximately every two years on interiors. Loose soil systems are not well suited for areas with any seismic activity. Reparations are only achieved by re-stuffing soil into the holes on the wall, which is both difficult and messy. Loose-soil systems should not be used in areas where there will be a lot of public interaction as they are quite messy and lose their soil little by little over time. Loose-soil systems with physical media erosion systems are well suited for all green wall applications.

Mat type systems tend to be either coir fibre or felt mats. Mat media are quite thin, even in multiple layers, and as such cannot support vibrant root systems of mature plants for more than three to five years before the roots overtake the mat and water is not able to adequately wick through the mats. The method of reparation of these systems is to replace large sections of the system at a time by cutting the mat out of the wall and replacing it with new mat. This process compromises the root structures of the neighbouring plants on the wall and often kills many surrounding plants in the reparation process.

Structural media are growth medium "blocks" that are not loose, nor mats, but incorporate the best features of both into a block that can be manufactured into various sizes, shapes and thicknesses. These media have the advantage that they do not break down for 10 to 15 years, can be made to have a higher or lower water holding capacity depending on the plant selection for the wall, can have their pH and EC's customized to suit the plants, and are easily handled for maintenance and replacements. They are the most robust option for a living wall for both exterior applications and for interior applications. They are also the best choice in areas where high-winds, seismic activity or heights need to be addressed in the design. Structural media are superior to the other media for their longevity and high-level of performance in a variety of circumstances. Depending on the installation, they do tend to be more expensive to install, but lower cost to maintain.

Irrigation and plant nutrition:

Green walls cannot be sustained without irrigation. Interruptions to the water supply are a common cause of plant failure on green walls. Systems designed with inbuilt irrigation should mitigate plant losses due to inconsistent moisture management, although errors can still occur. Automated, remotely controllable irrigation systems are used for walls in high profile locations, or in situations where access is challenging. Note that the quality, design and costs will vary between different systems. The most sophisticated systems enable the maintenance supervisor to keep track of the automated performance of the system, including the volume of irrigation delivered, its frequency, substrate moisture content, as well as pH and nutrient levels in the water supply. The settings can be overridden if needed; for instance, the frequency or duration of irrigation cycles may be increased on hot days. In hydroponic systems, plant nutrition is delivered by a fertilizer injection system that releases controlled doses of fertiliser into the irrigation system (fertigation). Management of fertigation systems and rates of delivery requires specialist knowledge, as it is more complex than fertilizing soil or growing media. Hydroponic systems require continual monitoring of pH, water hardness and total dissolved solids (TDS), and adjustment of these parameters where necessary.

Irrigation:

The irrigation system is designed to minimize water consumption. It consists of an automation-unit with equipment for control of nutrient injection and irrigation cycles. When a surface has a variation of sun exposures, the irrigation is divided into segments in order to program it specifically for each part. Within the multi-layered felt surface a drip-tube is integrated. Water consumption varies with heat and sun exposure, but compared to normal green spaces or a lawn, the consumption is normally lower.
It averages between 2-5 l/m2/day.

For hydroponic green wall systems, the fertigation system may apply 0.5-20 litres of irrigation solution per square metre perday. Internal green wall requirements are at the lower end of this range, and external green walls at the higher end. Irrigation cycles typically last a few minutes and will be required several times a day. Keeping irrigation volumes low minimises waste and reduces run-off. Irrigation run-off may be captured in a tank at the base of the wall and recycled back through the green wall system.  Green walls that use a high quality, water-retentive growing medium, and are not in an exposed or particularly hot location, may thrive on a weekly watering regime. In most simple, soil-based systems, including DIY systems, controlled release fertiliser is mixed in with the growing medium, rather than using a fertigation system. Irrigation must be available as soon as the plants are installed in the wall system. The irrigation system requires a water meter to monitor irrigation volume, and a pressure gauge to monitor the even application of water. The need for ongoing regular irrigation and the expectation that water will be used sustainably means that stored (harvested or recycled) water should be used whenever possible, so a pump is necessary.

Design / process:

Each vertical garden is given a unique design and selection of species. The composition of plants takes in consideration the specific environment where it will be built, such as the local- and micro climate, sun exposure and the surrounding context. The aim is to create a one of a kind and site-specific garden that stands beautiful through all the seasons of the year.

A well executed design is also a way to minimize the future maintenance demand of the garden. A plant's growth habit, size and behavior on a vertical surface is important knowledge for making the right combination of species, in order to keep the competition between plants at a healthy level. Choosing the right plant for the right place makes sense for any garden, but maybe even more so in a vertical garden..
A vertical garden can be installed in almost any location and as a living material, the potential of integrating plants in our urban environments is interesting. Places never thought of as possible could be inhabited by plants, like subway stations or other intensely frequented places where horizontal space is difficult to spare.

Light:


Direct sunlight can deliver over 100.000 lux whereas the average light level in an office is around 300-500 lux. Even if the least light demanding species are used, artificial light is normally necessary indoor. A few species will stay fine at 900 lux, but a slightly increased level at some parts of the surface will broaden the variation of species that can be used. An artificially illuminated surface has shifting light levels, due to the fact that light reduces with the square of the distance from the light source. Some areas might have 3.000 lux and others 900 lux. The plant design is made with this in mind, taking advantage of the higher levels for more demanding and interesting species.

General considerations:

  • Watering: Appropriate time
  • Carefull selection for wind prone areas (Succulent and hardy plants)
  • Removing the dried leaves
  • Keeping the structure clean
  • Disposing the water from drainage system
  • Pruning if necessary
  • Timely application of fertilizers
Benefits of Vertical gardening:
  • Aesthetic effects
  • Acts as natural insulation for hot and cold air and a save energy for your building
  • Reduces CO2 levels and increases oxygen and improved air quality
  • Conserves water and watering takes less effort
  • Sound absorption and noise absorption
  • Improves thermal insulation and energy efficiency
  • Provides protection to buildings from adverse temperature and hence improves the life expectancy of the buildings
  • Mitigate urban island heat effect
  • It  holds rain water, providing food and shelter for wildlife

DIY ( Do it Yourself) :

Target site Water proofing Fixing of frame Mounting cups on the frame Completed module
Or you can use garden trellis/nets to hand the pots to form a low cost vertical gardens

Vertical pillars:

 
 
 
Drilling the holes according to the spacing mentioned
 
Filling the pipe with gravel, sand, coir pith and water
 
Planting without disturbing the ball of earth

After planting

 

Certain DIY ideas for you to make simple and low cost vertical gardens in your houses

Green walls in various locations:

Indoor Vertical garden Public Buildings/ Apartments   Malls  
Universities/Airports/ Hospitals Streetscapes/ Bridges/ flyovers


Source:

Department of Floriculture and Landscaping

TNAU,Coimbatore-3.


Last Update : November 2014

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