So first things first: what is a green wall exactly? A green wall is a vertical garden, a system that attaches plants to vertical surfaces. Don’t get green walls mixed up with green façades, however. Green façades are made up of climbing plants, such as ivy, that grow directly on a wall from the ground.

A green wall uses either soil or an inorganic growing medium to support the plants and allow them to grow on the wall itself. The wall structure is typically composed of four elements: a framework, the growing medium, the plants and an irrigation system. Green walls can also be referred to as bio walls, eco walls, living walls or vertical gardens. They can be installed either inside or outside, where the plant selection will differ depending on the wall’s location and surrounding environment.

A mind–body–nature connection

Green walls help to encourage biophilia, which is our natural human connection with nature and other living things. Just being in the vicinity of living plants can make you feel more connected to the Earth.

A green wall uses either soil or an inorganic growing medium to support the plants and allow them to grow.

“Plants beautify and modify the environment in a way that improves a person’s feeling of wellbeing and their ability to cope with stress, to relax and to feel connected to the natural world,” says Patrick Belford, Garden designer at Inner City Nature. “Studies show that people react in a more moderate and mindful way to stressful stimuli when they have plants in their environment.

“Plants provide a low-stress and non-demanding pastime in their care and watering, which is an outlet for meditation and nurturing,” he explains.

Practical & positive ecological impact

A green wall has many worthwhile benefits through the creation of a more environmentally conscious living environment. It can help clean the air you breathe, create a barrier against noise pollution and encourage the flow of natural biodiversity.

“When placed inside, green walls can help reduce noise levels, as the plants in the green wall block high-frequency sounds and the structure it is built on can help reduce low-frequency noise,” explains Mark Paul, horticulturalist and founder of The Greenwall Company.

Installing a green wall in your home can also help to reduce your energy consumption costs as it provides a natural source of insulation. “In the warmer months [green walls] help to cool the air and in the cooler months they help keep the cool air out, which can reduce heating and cooling costs,” says Paul. This in turn assists in reducing the “urban heat-island effect”, whereby heated stone and brickwork gradually increase city temperatures from reradiated heat.

Another added benefit of green walls is they are water efficient due to the drip-irrigation system they use. Water drips down through the top plants to the bottom, where it is either drained away or pumped back up to begin the cycle again, meaning little water is wasted. Plants can also purify somewhat polluted water, such as greywater, so it can be reused.

Outdoor plant walls trap airborne dust particles, absorb pollutants and increase local humidity, which can encourage beneficial insects and birds to visit.

Interior spaces

Incorporating a green wall into your interior living space not only creates a stunning visual impact, it can actually make your home environment a healthier one as well.

“Introducing plants into your home has a number of benefits,” explains Belford. “Plants are very powerful in recycling the air within an interior space. Plants and the soil the plants grow in lock away VOCs (volatile organic compounds) that are off-gassed from furniture and fittings within the built environment.”

“The introduction of plants can help to clean the air and increase relative humidity levels to a ‘safer level’ where microbes are less likely to prosper.”

Plants do vary in their capabilities of filtering the air, however, so it does help to have an idea of what you are seeking to filter out. Given the amount of time we spend indoors these days, it’s worth thinking about what you are breathing in.

“In our modern lives we spend around 95 per cent of our time indoors,” says Chinese medicine practitioner and building biologist Lucinda Curran (EcoHealthSolutions.com.au). “Given that our buildings are meeting energy-efficient criteria, we are effectively building homes and workplaces that are like being inside a plastic bag. In some cases, the indoor air can be up to 10 times more polluted than the outdoor air.

“Our indoor air tends to be polluted by air fresheners, pesticides, off-gassing of furniture, cleaning and laundry products, personal-care products and more. Often ventilation is inadequate, too,” Curran adds. “The introduction of plants can help to clean the air and increase relative humidity levels to a ‘safer level’ where microbes are less likely to prosper.”

Exterior spaces

Exterior green walls are perfect for covering up an ugly wall and giving your outdoor area a visually enticing burst of green — without taking up any space. They can act as a barrier to street noise or as a living privacy screen, or can be used to divide different living zones. They can help provide shade from the sun or protection from the wind and can be added to any flat surface, including walls, fences or even your roof.

“Green walls are beautiful and act as a living art piece; they really bring life to any building, room or wall they are installed on,” says Paul.

In recent years, with the cost of city living soaring, it’s no secret that the size of the quintessential Australian home is being reduced. Living areas are often open-plan and multipurpose and the good old Aussie backyard is now more often than not a small box-like balcony or courtyard. Smaller living zones mean less room for plants as they can take up too much precious floor space. Adding a green wall to a modest outdoor area is an ideal way to incorporate a live element to your space without reducing your living or entertaining quarters.

Different types & styles

The practical nature of the green wall, in addition to its aesthetic and environmental benefits, means you won’t find yourself short of different varieties of living walls to incorporate into your home.

Green walls come in a vast array of different styles, designs and plant types. They can be made to measure to fit your own unique environment and meet your needs.

Installing a green wall in your home can help to reduce your energy consumption costs as it provides a natural source of insulation.

“There’s a number of different types of green walls and a number of companies producing different systems,” says garden designer Belford, who prefers a modular system as you can change individual plants when you feel like something new. “There are other systems that work using a felt-matting system, which is laid over the wall and the plants are either stapled to it or inserted in pockets. This is good as they sit flat to a wall but are more difficult to maintain if there are problems with plant losses.

“There are also systems that use standard pots arranged in a structure over the wall, but I personally think they look a bit daggy. Arranging the plants like soldiers in rows or blocks can be boring for the eye.”

There are literally thousands of appropriate plant species that can be used for your green wall, so you won’t have trouble sourcing a variety you like. “There are around 60,000 species of appropriate plants,” says horticulturist Paul. “None is terrestrial (grown from the ground) and all are either epiphytic or lithophytic (grown in or on rocks and trees), emanating from all over the world. Some examples of these are orchids, bromeliads, begonias and gesneriads.”

For interior walls, Belford recommends easy-care indoor plants from the tropics, such as spathiphyllum, aglaonema, calathea and philodendron.

For outside walls, a variety of succulents such as echeveria, sedums and crassula can look stunning. Liriopes, small hebe varieties and daisy bushes can all work well, depending on your local environment. Plants with water-holding stems and leaves, like pelargonium, begonia, peperomia and columnea are a good idea if you’re not big on maintenance or live in a dry climate. Plants with water-holding roots such mondo grass, dwarf agapanthus, ribbon plant and philodendron work brilliantly in this way as well.

If you like the idea of a kitchen garden, try an edible green wall. Hardy herbs such as thyme, sage, oregano and rosemary are perfect, particularly for up the top of your green wall, as they don’t need as much water as other varieties. With a living wall made of herbs you also get the bonus of the amazing scent they exude.

Visual impact

The size or shape of a green wall can be whatever works for your space but if you want to create a wall that doubles as a living artwork, composition is key to creating and maintaining texture and visual interest.

If you like the idea of a kitchen garden, try an edible green wall.

“A green wall for me is about the visual display of the plants,” says Belford. “The integration of the movement of colour, texture and form and how it moves throughout the composition is a make or break in how well it will be received.

“If the plant material creates drifts of pattern and texture through the wall, the eye will be excited and soothed and this will create a more positive experience for the viewer and the surrounding environment.”

Potential drawbacks

The only drawback to a green wall comes down to expenses and work — which is often a drawback to many things, if truth be told. According to Belford, “Setting up a green wall can be expensive, particularly if it is inside, as there will be plumbing and maybe some engineering required to safely install something that requires water in an interior.”

The green wall can also be expensive to replace if it fails, as dead plants are messy and don’t smell the best. Dead plants can also cause pest problems, says Belford. “This will also have a negative impact on the psyche. No plants are better than obviously sick or dead plants.”

As with any living thing, a green wall needs the proper care and environment to thrive. Even if it uses the hardiest of plants, it needs to be set up in the right surrounds. “You must have power, water and light for your green wall to grow,” adds Paul. “If not enough natural light is available for the wall to grow, lighting must be added to the wall — which can sometimes cost as much or more than the green wall itself!”

All green walls should be on a fuss-free and water-efficient automatic irrigation system and be monitored and adjusted throughout the year. Any problems with pests should be spotted and troubleshot early on to prevent extra work and potential casualties.

Says Belford, “Interior green walls are particularly susceptible to insect attack, which can create havoc for the wall. Overwatering is a common cause of insect infestation, so monitoring is important. The wall will also need trimming, feeding and some plant replacement throughout the year to keep it fresh. About a 5 per cent loss of plants per year from a wall is to be expected.”

DIY vs professional installation

Depending on the type and scale of wall you want to create, you can DIY your own green wall. There are many tutorials on the net about how to do so, as well as a number of kits you can buy from your local nursery or garden centre. If you want to install an irrigation system or lighting features or are not sure about what plants are suited to your surrounds, professional help may be worthwhile in the long run.

“Green walls are ideally designed, installed and maintained by a professional,” says Belford. “For a green wall to be successful, the plant selection has to be perfect for the location and conditions, more so than in most other gardening scenarios. Intimate knowledge of plants will enable the most immediate and impressive result in the short and long term.”

If your wall is inside or outside, you do need to consider its aspect. “Whether it is by a sunny window or receives only filtered light, this has an enormous bearing on what plants are required,” Belford continues.

“The installation needs to be done in a way that provides for easy maintenance over the life of the wall, so the irrigation system reaches all plants, and so the plants are positioned in a way that grows into a harmonious and artistic display.”