Green Services Direct

It’s a growing fashion for both interior and exterior walls of buildings

Green space in many homes is seriously squeezed be it a backyard, balcony, garden or roof terrace. Smaller plots are often paved for practical reasons and planting severely restricted to just a few pots. Covering walls with plants can enhance the smallest of spaces and, reconnect people with nature.

With thanks to Jessica Wigmore, of Biotecture for her help with this article.

What are green walls?

Green walls, living walls, eco walls and vertical gardens are all different names for much the same thing. Basically, they are a way of growing plants onto a vertical surface. They can offer the perfect solution for greening bare walls and extending the planting footage of garden. Wigmore said: “Vertical gardens are a space-efficient way to incorporate more greenery into smaller residential spaces. They allow you to enjoy the benefits of gardening without taking up valuable floor space.”

Image supplied by Simon Orchard Garden Design, using the PlantBox system

Vertical gardens can be on the exterior or interior walls of buildings as part of biophilic design. Ideally, the result should be a beautiful, rich tapestry of foliage and flowers, like living art.

Green walls may seem like a modern design trend, but their roots go way back. The idea to create a living green wall was first patented by Stanley Hart White in the 1930s and popularised by French botanist Patric Blanc. Architects who have embraced green walls include Renzo Piano, co-designer of the Pompidou Centre in Paris. In the UK, the Rubens hotel in London Victoria has an impressive green wall of foliage and herbaceous plants standing at 350-metres tall.

What are the benefits?

As gardens get smaller, making use of all the surfaces for planting makes a lot of sense and can look striking. In addition to looking good, green walls also tick many environmental boxes.  Outdoor living walls attract and support local biodiversity, providing a habitat for insects, butterflies and even birds.

Plants also insulate buildings and cool our increasingly sweltering cities in the summer. The ‘urban heat island’ heat effect means that our predominately concrete cities can be up to 6C hotter than the surrounding countryside.

At Edgeware Road Underground Station, Transport for London commissioned a green wall to tackle air pollution at a busy road intersection. Crossrail also commissioned an eco-wall at its site in Park Lane. The aim? To enhance the greenery of their site while tackling noise and dust pollution.

Living walls are popping up everywhere from city centres to rooftop balconies and inside offices and homes. We typically spend 90 per cent of our time indoors. Indoor living walls can improve air quality, leading to a healthier environment. “Plants naturally purify the air by removing pollutants and releasing oxygen,” explained Wigmore.

Putting plants into the built environment is believed to enhance comfort, and wellbeing. “Living walls can create a calming and tranquil atmosphere, providing a connection to nature that promotes relaxation,” said Wigmore.

How do I create my own living green wall?

The simplest way of greening walls is by covering it with ivy or some other self-attaching climber. Plants such as pyracantha can also provide green cover for a bare wall. On the downside, it may take a few years for climbing plants to achieve the desired effect and they can damage brick walls and timber panels.

Other solutions range from wooden trellises to wires for the climbers to cling to, providing a gap of insulating air between the living plants and the building.  In addition, there are clever modular living wall systems. These are stackable planter boxes or troughs that can be fixed to a wall and don’t require the plants to do the climbing. They can be a simple and quick way to transform an unsightly wall.

For instance, PlantBox’ is a clever vertical garden with stackable troughs. Made from 100% recycled plastic in England, it was a finalist of the RHS Chelsea Sustainable Product of the Year 2021. Freestanding or wall-mounted, the units can simply be attached to courtyard or boundary walls, fence uprights, balcony railings, roof gardens, patio, terraces or conservatory walls up to eight metres in height.

Issues to consider

Before installing a green wall evaluate the amount of sunlight any plants will receive. South and west-facing walls typically get most light throughout the day while north and east-facing walls tend to be shady. “It’s possible to put a living wall in a shady spot but shade tolerant plants, such as ferns and heuchera will be required. In sunnier spots, you can use a wider variety of planting including flowering plants to attract pollinators. The amount of sunlight your living wall gets will also influence the amount of water it needs,” says Wigmore.

It’s also important to check your wall, fence or balcony can support the additional weight of the living wall, especially when it’s wet. One advantage of PlantBox is that it’s ground bearing, so it doesn’t put additional weight on the supporting structure. It simply needs tying back to the wall or fence with wall ties.

Other issues to consider include irrigation. Smaller walls can be manually watered but larger ones might need an irrigation system. Many modular vertical gardens come with in-built water reservoirs. Alternatively, a simple strip of pipeline attached to a tap and a tap timer can work well, said Wigmore.

Don’t forget the aesthetics and design. Green walls can be planted for a variety of looks from a loose, natural style to a more formal and eye-catching mosaic pattern.   “Plan the design and layout of your vertical garden for visual appeal. Consider colour combinations, plant textures, and overall aesthetics that complement your balcony and living space,” said Wigmore.

Which are the best plants?

Low maintenance plants that spread quickly and love indirect sunlight are best. Varieties like sedum, crassula, echeveria, ferns and ivy are all great to include in your green wall scheme. Consider also planting herbs like rosemary and thyme as well as bulbs to provide seasonal colour.

Perennials are best as they come back year after year. Top tips include choosing foliage over flowers and opting for sunny or shade-loving schemes depending on the amount of sunlight your plants will receive. Basically choose plants that match the light and moisture conditions on offer. This gives plants the best chances of survival.

Some living wall systems  come with plants pre-chosen by experts to suit different conditions, such as sunny or shady walls. Check out Gardeninabox.com The snap-together kits come with classic evergreen plants and peat-free compost included. Prices range from £143 for three boxes to £899 for 20 boxes. The website has a handy calculator to help you work out how many boxes you need.

Spring is the best time to create your living wall as the plants are coming into active growth and will establish quickly. Add plants at as small as size as possible, ideally as plugs.

Living walls are a brilliant way to add some greenery to your home and  garden. They can be used to cover a boring or ugly wall, create a focal point or to enhance a seating area. Try and put your living wall in the space you are most likely to enjoy it.