Green walls are a concept that Australians are embracing in commercial and residential spaces.
Designed by world renowned Botanist Patrick Blanc, One Central Park in Sydney features 23 green walls comprised of 35,000 wall plants and 85,000 facade plants. The vegetation is made up of over 350 different species of plants, most of which are native species to withstand the Australian climate. The first-class lounges of Qantas in Sydney and Melbourne also have Patrick Blanc’s installations in pride of place.
They become living works of art that transform any office building, commercial space, backyard, balcony or courtyard.
A striking feature could be a vertical and/or horizontal pattern in freestanding columns and walls planted out with philodendrons, ivies and ferns and used as a stunning room divider. A well-designed wall garden will last for 10 years or more and ultimately inspire us to appreciate nature’s surprises.
Man has been growing vertical gardens for over two thousand years, ever since the Hanging Gardens of Babylon where massive hanging gardens of trees and shrubs cascaded down from the Babylon towers.
A vertical garden on the outside walls of buildings is very efficient and aids in lowering energy consumption, both in winter by protecting the building from the cold, and in summer by providing a natural cooling system. Outdoor vertical gardens use about 5 litres of water per square metre a day, which is about a third of what a traditional garden uses.
Likewise, the look and feel of living greenery indoors with trickling water is very soothing and cooling. Having a vertical garden indoors results in the absorption of odours, a cooler environment, suppression of noise and a unique restful ambience.
Vertical gardens are especially good for our health when installed indoors. Indoor air contains many Volatile Organic Compounds (VOCs) that can pose a significant health risk. The CSIRO estimates the health cost of poor indoor air quality in Australia may be as high as $12 billion per annum.
VOCs, such as formaldehyde from wall panelling and furniture, and Xylene and Tolyene, from paints and carpets are but a few of the mainl VOCs identified in indoor air. Many of these VOCs are known carcinogens and together they contribute toward a health problem called ‘Sick Building Syndrome’; the symptoms of which can include headaches, nausea, fatigue and eye, nose and skin irritations.
Research proves that VOCs are removed by microorganisms living in the soil near the roots of indoor plants and that three plants per 10 square metres of office space can significantly remove the level of VOCs in the air.
In fact, the more polluted the indoor air, the greater the uptake of VOCs by the plants!
A green wall/living wall/vertical garden is a wall partially or completely covered with greenery that includes a growing medium, such as soil, water or a substrate. Most green walls include an integrated water delivery system. These unique structures can either be freestanding and parallel to or actually attached to a wall.
TIP: Collection trays should be positioned at ground level to allow overflow water to be discharged or recycled. If the water is being recycled, add a general-purpose soluble fertiliser (with nitrogen, phosphorous and potassium) periodically to the water for better plant health.
There are also vertical gardens using artificial plants and although they offer only an aesthetic appeal, they have their place. There is no maintenance, they always look their best, they can be installed in any aspect and they are an instant fix to a drab wall. We can even buy direct online now thanks to www.verticalgardensdirect.com.au and www.designerverticalgardens.com.au and www.greeneryimports.com.au
Vertical gardens can be used to cover entrance walls, blank walls behind bars, and in restaurants and reception areas.
With thought, they can be positioned as screens, room dividers, privacy curtain and hung on existing boundary walls.
They can be planted out with almost any small plant either mixed or with specific groups of plants such as succulents, herbs or vegetables. Plants should be carefully chosen to give a contrasting design using texture and colour, creating swathes of living colour.
TIP: If your clients decide to grow vegetables and herbs vertically, they must be in the sun facing north, and design it such that the shade cast by some of the bigger plants will help to cool less heat-tolerant plants, such as parsley.
There are numerous wall garden modules on the market that vary enormously in price, depending on the quality of materials used and the complexity of the structures including drip irrigation systems. Often, they are comprised of modules assembled from high strength, lightweight structural panels, incorporating interlocking snap-on clips for easy assembly. They can be fixed to any structural wall including brick, concrete, wood, sheet metal, drywall and other surfaces.
TIP: Modules are best pre-planted to allow proper establishment to occur before your installation on site. Water storing crystals infused with a seaweed solution work a treat when planting.
Here’s a cost-effective method for creating a vertical herb garden outdoors. A great range of herbs can be planted including: coriander, sage, chives, basil and mint, lettuce, parsley and rosemary.
Construct a strong waterproof frame (marine ply works well). Either fix it to the wall or make it freestanding.
The inert growing medium used is ceiling insulation, which acts as a super sponge, holding many times its weight in water.
The insulation slabs are held in place by shade cloth.
The next step is setting up the reticulation system. A pipe comes out of the fully submersible pump, which is situated at the base of the frame in a mini reservoir. The size of the pump and pipe will be determined by the head height i.e. how high you want to pump the water. The higher you go the more expensive the pump. Pump size and cost increases dramatically if you go over two metres high. Timers control the watering, which should happen four times a day.
The piping extends to the top and along the top edge of the frame, with drippers that plunge into the insulation. This creates a circulating hydroponic system.
Make small incisions into the shade cloth and tiny planting holes with your fingers into the insulation.
Knock as much soil as possible off the roots of the plants before tucking roots into the prepared pocket.
TIP: Use a small piece of wet insulation to hold plants in place.
Here’s another simple method of building a living wall, this time to support succulents:
Construct a cage from galvanised mesh sheets or ‘reo’, which is commonly used for reinforcing concrete.
Next, line the cage with some fabric such as Geotech, fly screen or shade sail to prevent the growing media from coming out.
TIP: Use a free draining succulent mix with vermiculite or coco fibre potting mix and sphagnum moss or try mixing some orchid potting mix and premium potting mix together with some vermiculite.
Green walls can also be cleaned and reused for seasonal plantings, which adds interest to commercial and office spaces. Therefore, some aspects of the wall need to be monitored and maintained more closely. Consider offering your client a maintenance program to ensure that the plants remain healthy and vibrant.