AS a global society, we are at a junction where our decisions today will help shape the environment and climate into which our children and grandchildren will be born. But this is not just about the future. There are immediate benefits to keeping pollutants out of our environment: cleaner air, lower energy costs, improved aesthetics and new growth industries.
The urban green revolution is all around us. From lush balconies and roof gardens, green walls and innovative urban food-growing schemes, initiatives to bring nature back as our cities continue to grow. Green walls are particularly suitable for cities, as they allow good use of available vertical surface areas. There is no need to restrict planting to the ground. They are also suitable in arid areas, as the circulating water on a vertical wall is less likely to evaporate than in horizontal gardens.
The living green wall could also function for urban agriculture, urban gardening, or for its beauty as art. Green Walls have seen a recent surge in popularity. Many iconic green walls have been constructed by institutions and in public places such as Airports and Shopping Malls are now becoming common, and rightly so. From the smallest house to the biggest development, bringing the walls to life can have surprising benefits. Every tiny patch of planting brings benefit to those who live and work there.
In A Challenging world of flash floods and unforgiving heat-baked concrete is transformed by foliage-dappled sunlight and fresh scents. Green Walls are suitable for urban environments where the plants reduce overall temperatures of the building. ‘‘The primary cause of heat build-up in cities is insolation, the absorption of solar radiation by roads and buildings in the city and the storage of this heat in the building material and its subsequently re-radiation. Plant surface however, as a result of transpiration, do not rise more than 4-50C above the ambient and sometimes cooler.
Green walls may also be a means for water reuse. The plants may purify slightly polluted water by absorbing the dissolved nutrients. Bacterial mineralize the organic components to make them available to the plants. It also reduces local flooding by absorbing rainwater, both at root level and by holding it in the canopy of foliage, while planted areas are known to increase local biodiversity. Foliage on or around a building acts as insulating jacket which keeps the building cooler in summer and warmer in temperate weather. This not only reduces carbon emissions but saves on heating and air-conditioning bills.
Ten, fifteen years ago, people thought it was far-fetched, as the technology becomes accepted and companies start to invest, the future looks bright. Green walls are increasingly popular feature in domestic gardens. Vertical planting is an excellent use of space and can substantially increase the planting area in a small garden or roof terrace. And for grow-your-own food enthusiast, herbs, vegetables and smaller fruits thrive. Some systems are designed specifically for herbs and vegetables and vertical gardens like these can be a great solution to growing food in lack of space. Living walls can be fitted to both new buildings and refurbishments, from small experimental garden projects to large commercial developments. They can be installed inside or attached to the outside of buildings. The flexibility of living green walls makes them perfect for all environments.
Do Living Green Walls Work?
Designed to create drifts of color throughout the year and provide forage for pollinators, the vertical garden imbues a once featureless façade with charm and character.
There are three main ways to make a Green Wall.
Living green walls are commonly hydroponic systems irrigated by a drip-irrigation method. Green walls are organized into panel and tray systems of free standing walls, meaning there is a small wall suitable for any space Panel Systems, have plants pre-grown into the panels and can be used inside or out, and in any climate.
Tray system which is popular for indoor displays. Plants are pre-grown off site and inserted into the wall, which offers a great degree of versatility that can be exploited to cover entire surfaces or designed as living art Free Standing walls are most commonly used indoors and are most easily changed, either b y changing the location or changing the plants.
Conventionally, plants are grown up a trellis or wire. This is an inexpensive option but it takes time for plants to establish. Then there are two modern alternatives, both of which involve fixing irrigated planting modules to a frame that is separated from the building with an air gap and geo-textile membrane.
Green Walls, are, however, not always welcomed and there are frequent objections from people who have reservations about the cost – or misunderstand the process.
As with all new technologies green wall systems don’t come cheap. In context of construction, the cost is minimal and the benefits are considerable. A green wall will protect the underlying structure from sun, rain, frost and will extend the life of the building. Green installations could double or triple the life of the surface to which they are attached. There are a number of pricing levels to suit your budget. Large scale green walls are built and maintained by professionals but for ordinary gardeners, cheaper planting pockets and modular systems are available. These can be hung from house walls or attached to a fence.
In addition to the hardware and engineering, large urban greening schemes require a fair bit of gardening know-how, not least because they are far more exposed than conventional gardens.
As vertical greening becomes more popular and more ambitious, the horticultural, industry, too, must adapt to its demands. There is need for architectural horticultural and engineering skills. The palette of proven plants is increasing as specialists are looking for plant diversity, functionality or pollinator benefits, sourcing can be an issue.
Horticulture has an image problem: gardening is often seen as a pastime for old men and women and not a career for the educated. As a result, it is a struggle to find professionals with sufficiently good skills. And it seems unlikely that the ability to abseil off the top of a building to plant up a green wall is on the professional criteria. Horticultural professionals are not as well respected as engineers or architects. A potential lack of horticulturists is a problem, but one is optimistic. This would change in the near future. Living Green Walls have already come a long way and as the technology becomes accepted and as the market is stimulated, we should also invest in training. Urban Greening might just open the door on a new world of gardening career opportunity.
As a career choice it’s a very, very exciting time to become an urban greening specialist. For the industry, the future is bright. Not just in the major projects and big money coming in, but as lots of small projects coalesce into a greener city.
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