Sustainable Garden Design Perth & Fremantle, Australia
Vertical Gardens

What are vertical gardens?
Vertical gardens are simply gardens designed to grow on vertical surfaces on either existing buildings or stand alone structures specifically designed for the purpose. This type of garden can take on many forms either consisting of a number of vessels which are reticulated, usually using more conventional watering systems, or through the use of waterproofed walls covered with pockets of felt and fed through a more elaborate hydroponic system. They can be as simple as stainless steel wire or trellis with grape vines growing on it, espaliered fruit trees or more complex growing hydroponic systems or greywater recycling systems.

The second system often referred to as a greenwall or mur vegetal has been pioneered by the French botanist Patrick Blanc who has designed extensive walls which cover whole sections of buildings. There are a number of companies which offer modulated systems which emulate this method and are now available in Australia.

What style of vertical garden do we usually specialise in?
Our company has targeted smaller residential style vertical gardens which provide a sculptural feature either as a point of inspiration within the garden or as a method of providing a source of food in smaller city gardens.

The structures that we have used usually have a metal frame with suspended zincalume or stainless steel vessels which contain the soil and plants. The benefit of these systems is that they easily tie in with the existing reticulation system.

In the more decorative designs we prefer to use succulents which provide beautiful architectural shape and require little or no water depending on the species.

With our new systems it is even possible to develop greenwalls which can work within the interior of the home.

What are the key aspects of creating an inspirational vertical garden?

Good structure
First, you need to have a very well structured wall to use as your starting point, or you may need to structurally reinforce your wall so it can take on the significant amounts of extra weight you will be adding.

Kits
Most green wall kits come with modular forms that are assembled in accordance with the instructions and applied to a frame that then secured to the selected wall. Some forms of vertical garden come as a wall panel that is self-supporting. Many such kits are not readily sold off the shelf in Perth and may require you to investigate further on the internet if you wish to attempt the process yourself.

Soil Medium
Fill the framework of the wall with high quality, well-draining potting mix if you are building your own vertical garden. These contain slow release fertilisers and soil wetting agents both essential for plant health. Some kits come with a supply of inorganic growing medium to use as this does not break down but may require the occasional use of liquid fertiliser to maintain the healthy growth of the plants. Products such as Seasol or Powerfeed should be suitable for most plant species.

Drainage
Make sure you set up a tray or other drainage that will conduct excess water that flows to the bottom safely away. This can in some systems be recirculated through a small pump in the collection tray. It is possible to obtain smaller solar powered for this purpose but once again it is difficult to buy these off the shelf in Perth.

Light and shade
Also make sure indoor living walls have the correct amount of light for the species that you have selected. If you are trying to create a waterwise vertical garden, the more sun on the wall, the faster the soil or root medium will dry out.

Plant Selection
When selecting plant species it is best to steer away from large plants that will put a lot of pressure on the angled root area when growing a pocket system vertical garden. The best selections are lightweight leafy plants, plants that naturally cascade and plants that grow in mounds close to the root area. Succulents, for example, make an excellent choice as most will hug the wall and come in varied and interesting shapes and colours providing a kind of living tapestry. One of my favourite species include smaller leafed philodendrons which are more suitable for shaded vertical gardens but provide a feeling of lushness and in the right environment require very little water.

Irrigation and waterproofing
The key element in the success of your vertical garden is how you water it. In many instances you can utilise an already existing reticulation system and use drip or subsurface irrigation on existing lines. A key to the creation of a vertical wall is that you need to protect the surface of the wall that is supporting it with either a kind of waterproof paint or impermeable layer. Creating pockets for plants to anchor their roots into with netafim drip irrigation tubing will maintain the green wall effect.

Andrew Beck
andrew@sustainablegardendesignperth.com