Vertical Gardens in Landscape Design

As a member of Greenroofs Australasia, I am often asked to comment on the viability of vertical gardens landscape design.

With the ever increasing population density within cities and the inner suburbs the days of the iconic aussie backyard appear to be drawing to a close.

The single home on the quarter acre block is now replaced with apartments and townhouses. Balconies and “alfresco” voids are becoming the norm.

For those in apartment buildings, a garden might consist of a pot plant, a window box or a small balcony. In the suburbs, townhouses offer an “al fresco” dining area that devours any remaining garden space.

To counter this, more inventive ways to green an outdoor space needed to be devised. One of these greening methods is the Vertical Garden. They are being introduced into the mainstream via various systems (both DIY and ready made) that can help people increase the amount of plant material within their home without impinging greatly on their size poor outdoor areas.

With an ever-increasing number of systems being introduced to the domestic market some research is required when deciding on the right system.

A vertical garden can be a little temperamental and there are lots of elements to consider if you’re going to have one that thrives sustainably. Your investigation check list is as follows.

1. Energy

   Energy costs must also be factored into the equation. For example, a horticultural felt-based system survives with water running up and down its wall every day. If indoors, it may also require artificial lighting, adding to the energy costs. Although the cost can be minimised by choosing low light plants for indoors, it will always be difficult to make an indoor vertical garden truly self sustainable.

2. Location

   Location is a key factor is where you want to build your vertical garden. Indoor green walls are seen in high~rise apartments and in this case a modular hydroponic system may work best. Small components allow for ease of installation and removal of soil in your home keeps the system clean.
   An outdoor vertical garden can work well to hide unsightly neighbouring views or introduce plants to a balcony or courtyard. In this case any system would work, but what comes into play here is aspect. North and West facing walls will be problematic to sustain as direct sun can dry out and cook the root system quickly.

3. Light

   In my experience, light is the biggest challenge. Not so much the amount of light, but the balance. Getting light to wash across the whole vertical space evenly is the challenge. To assist you can compensate with your plant choice (low light species at the bottom).

4. Irrigation

   Vertical gardens are no different to any other garden, in fact if you choose a hydroponic type system, water and feed is critical. To add to this if you consider a system that requires a constant flow of water there is a single point of failure at the pump. When the pump dies, so do the plants.
   Most systems would also require daily watering, especially in summer, unless planted with particularly hardy species. When watering, rainwater is best as it contains many natural nutrients perfect for plants and helps with the feeding. If using a substrate based system select a good quality potting mix and watering crystals. This will go a long way to maximising water efficiency.

5. Plants

   Plant selection is crucial to further reduce the amount of watering your wall will need, “lt’s best to consider drought tolerant plants and with indoor plants, those with low light requirements are best.

Although there is a little more than meets the eye with having a vertical garden they have enormous health and environmental benefits and it is something every city dweller should seriously consider.