Written by Marcel Van Drongelen
Plants play an important role in the sustainability of our urban environment. And there is a growing international trend for developers and city councils to include green walls and roof gardens in their designs, not only for environmental benefits, but also for the aesthetic impact. They even work inside. Interior green walls in homes and offices improve air quality by removing pollutants and regulating humidity levels. They also provide a sense of connection with the natural environment. Under Auckland City Council’s Unitary Plan, fringe suburbs are now experiencing inevitable urban intensification. Green walls and roofs offer a fantastic solution to maintaining the natural environment amongst these concentrated new developments and city spaces.
Natural Habitats are a company at the leading edge of contemporary landscape design and green build solutions. They created the first green wall containing New Zealand natives in 2009 and have numerous architectural landscape awards to their name. They have also been involved in some of the country’s largest infrastructure, civic and commercial works, including the two, 3-storey-high green walls in the Britomart precinct and a 60m2 green wall in the bar of the Novotel at Auckland Airport.
We caught up with Rob Champion, the ‘green thumbs’ of Natural Habitats’ technology division to understand more about the design and installation of green walls – especially in the home environment. He told us that he’d seen a definite increase in residential green-wall projects over the past couple of years – and he put this down to homeowners’ greater understanding of the importance and benefits of incorporating plants in their day-to-day lives.
So how do they work?
“The system comprises panels manufactured from marine-grade, aluminium mesh baskets which are then lined with a synthetic textile used to hold the ‘medium’ for the plants to grow in – much like a bed mattress enclosed in an metal frame,” explains, Rob. “The growing ‘medium’ inside the mattress contains largely inert matter with some organic particles and nutrients which are then seeded with soil flora to encourage good growth and a healthy community.”“The seedlings are grown off-site for three to six months,” he continues to explain. “Initially, the panels are laid flat, so the plants can settle in and root down into the back of the panels, then gradually tilted as the plants grow so that when they are moved into place they are ready to start their new life as a vertical garden.”
Natural Habitats has also adapted this system for roof gardens. Eco pillows are made from the same textile and growing media as the green walls, but with a lighter and finer mesh.
Diverse choice of plants
“We specialise in New Zealand natives and try to incorporate rare, unusual and endangered native plants into our designs.”
One of the unique aspects of this type of green wall is that they allow for the use of plants that are not normally found in landscaping projects. Both epiphytic (plants that grow harmlessly upon another plant) and Lithophytic plants (plants that grow on rocks) thrive in this system, evoking a sense of the New Zealand bush in your own back yard. “For most projects the team go out into the local environment and look at what is growing naturally to use as a guide for the plant palette on the wall" says, Rob.
There are a huge range of plants, both native and exotic, that can be selected to achieve a multitude of effects – lush green walls, ones with texture and colour, a focus on bio diversity, or for a purely decorative effect.
Easy to install and maintain
“Any water can be reticulated back through the system or left to drain into garden beds below, depending on location and tank size.”
Once grown, the panels are transported to site and secured to a wall with struts and brackets. They look great straight away and will grow over time and develop further. Each panel contains an irrigation and nutrient-dosing system that ensures all feeding requirements are met. “The system is very water efficient because we don’t spray water onto the plants, but water the roots directly from within the panel itself,” he explains.
There is some maintenance involved, including checking water and nutrient levels, grooming and pruning, and putting in new plants if something dies naturally – all the principles of a normal garden still apply, just on the vertical.
Fully compliant for peace of mind
The system has been certified by Auckland Council and carries a 10-year warranty. It has been in operation for around 25 years worldwide, and there has never been a case of any panels degrading, or becoming dysfunctional.
So, whether you are a developer, commercial property owner, or a homeowner, consider a green wall or roof – it’s an eco artwork that will add impact and value to your property.