Definition of a Living Wall
A living wall is nothing more than a wall partially or completely covered in vegetation.
Larger scale commercial projects can cover hundreds of square meters, reducing GHG emissions, energy consumption (and loss), the urban heat island effect and even sound insulation. And we’re all well aware of the wellbeing benefits associated with green spaces.
But a smaller, DIY living wall – whilst it has some of these benefits – can be as simple as a panel with planters attached to to it, hung vertically on the side of a wall or shed.
Types of Green Wall Systems
There are five primary types of green wall systems:
- Panel / modular green wall systems
- Tray living wall systems
- Freestanding green wall systems
- Loose media systems
- Green facades
Panel / Modular Green Walls
Panel / modular living wall systems are – relatively – self-explanatory. Plants are usually pre-grown into panels that can be used in virtually any sort of climate.
These are simple to setup and can be installed fully grown for an instantaneous green effect. As the plants are grown for a couple of months in advance and require more maintenance and installation than your typically DIY green wall project they tend to be more expensive.
What is fantastic about them is that they’re designed to be attached and fixed to an existing structure – and completely customisable. So really you can use them in or outdoors and cultivate them to fit a certain aesthetic.
Ultimately if you’re willing to spend the money it will certainly be nicer than the DIY job you manage to put together for £150.
Living Wall Tray Systems
Much like in panel / modular systems, plants in tray systems are grown off-site and inserted into the wall in smaller trays.
This provides a greater level of design flexibility and future feng-shui, for when you get bored of the arrangement. They’re incredibly easy to remove and replace – equally great for when your plants inevitably die or you fancy an upgrade.
Each individual tray is designed to hold a set amount of water, delivered equally throughout the tray. Their orientation also means neither water nor soil spills forward – perfect for indoor environments.
But it’s not all sunshine and rosy cheeks when it comes to tray systems. Because the plants have to be rooted in soil they create an environment susceptible to mould, fungus and unwanted bugs. And they have to be replaced regularly which obviously increases your living wall’s cost – and maintenance – associated with them.
Freestanding Living Walls
Freestanding walls are the smallest major type of living wall available.
As the name suggests they’re movable, freestanding green walls that can be placed in in or outdoor settings.
Really they’re superb for temporary spaces, designs, or for someone who doesn’t want to commit to a long-term wall-based decision.
We’ve also seen some really brilliant uses of them as room dividers. But really these are a fantastic option for those of you looking to inject some green into your home (or cover up a long-forgotten shed or outside wall) without having to compromise the structural integrity of your property.
Loose Media Systems
Loose media systems have their soil packed into a bag and are then hung onto a shelf or wall. Really these are a DIY lovers dream when it comes to green walls.
Typically the growing medium needs to be replaced annually on exteriors and every 2 in a interior setup.
But these are only really suitable for smaller DIY projects for a number of reasons. Primarily their lack of stability.
The soil and plant is only held in a bag, so on a larger wall with prevailing winds there’s a danger the whole thing could blow off. So the aspect of your wall is important here when it comes to prevailing winds.
Green – or climbing – facades aren’t technically classified as a living wall. But for the purposes of this article it makes sense to include them for comparison.
Simple climbing plants, like ivy, are planted at the base of the wall and grow up a framework attached to the wall. Frames are often used to encourage the direction of growth or support different plant species on their ‘journey.’
Types of Irrigation Systems for Living Walls
Commonly there are two types of water management systems associated with green walls.
Most good quality, larger living walls are irrigated with an automatic drip irrigation system.
These systems have multiple nozzle heads to water each plant and the premium ones can be controlled by a timer, releasing a set amount of water into each plant everyday.
These systems link into the building’s plumbing and are significantly more efficient than a tank system.
Tank systems require manual refilling and – because they don’t tap into the building’s water source – require more significant maintenance and upkeep than a hydroponic system.
And as they don’t recycle unused water they create more waste and are ultimately less efficient.
Types of Soil Systems for Living Walls
There are two types of soil systems for living walls – soil-less (hydroponic) systems and substrate based systems – soil-less (hydroponic) systems and substrate-based systems.
Hydroponic systems are generally grown on pre-constructed panels prior to installation using a specialist growing medium. When they’re ready they’re attached to a structure pre-established on the side of the wall.
Hydroponic systems are expensive. And generally suitable for larger scale commercial projects. But they’re a fascinating opportunity for someone looking to create a premium indoor green wall that minimises the potential for mould or soil damage.
Soil-based systems use troughs or containers that are either built into the wall or attached onto it.
The substrate used is exactly the same type of soil you would use on a green roof:
- Porous – a free-draining medium
- Made from natural, recycled materials
This type of substrate allows for simple irrigation systems, reducing installation and maintenance costs. And if you’re looking for a DIY project this is certainly the right option.
The downside is – of course – the weight. Soil isn’t particularly light and adding 10s of kilograms of planting materials onto a wall can be a little nerve-wracking.