Extreme gardening on the 92nd floor of the Eureka Tower

On the 92nd level of Melbourne's Eureka Tower, two little plants have survived for months without soil or direct water. Caged and strapped to a rusty pipe, they endure winds of up to 200km/h at their lonely outpost high above the city.

The pioneering installation – thought to be the tallest rooftop garden in the world – is part of an experiment to see if it could be possible to grow plants on top of every building in the city centre. 
While "green walls" and "urban forests" are often spruiked in glossy brochures for new skyscrapers, they are not always a success.  Like the top of a cliff, the tips of high-rise towers can be inhospitable.

An artist's impression of Melbourne covered in rooftop gardens and roadway park created by Anton Malishev as part of the City of Melbourne's Urban Forest Art and Design competition. Photo: Anton Malishev

For the past eight months, ecological artist Lloyd Godman and his team have been breaking new ground on top of Melbourne's tallest building. They have installed eight Tillandsia flowering plants on levels 56, 65, 91 and 92, the very top of the 297-metre building.

Dubbed "air plants", these natives of South America do not require soil or watering but soak up the water droplets that fall onto their leaves. They are also unique because they grow during the night, vacuuming up pollution from the city during the evening peak hour.

The shrubs highest up in the most hostile location on the Eureka Tower were also growing the fastest – probably because they were getting more moisture, Mr Goodman said.

A mature Tillandsia.

It is his hope to eventually install "hundreds of thousands" of Tillandsia on the outside landings of the building, and all across the city
Melbourne City Council has commissioned a picture of a similar grand, green dream.
It will become so common for plants to grow across buildings that those that haven't been "terra-scaped" will look "old-fashioned", city experts say.

Tiny Tillandsia plant growing on top of Eureka Tower Photo: Lloyd Godman

Melbourne University urban planning Professor Brendan Gleeson said the first stage of a "green renovation" of Melbourne would be the widespread installation of green roofs. He said some roads could also be torn up and turned into strips of forests with walking paths and bike lanes.

Plants on buildings are said to be an answer to a number of 21st-century problems faced by cities. Melbourne's high-rise towers are vulnerable to heatwaves because they would have to be evacuated if their air-conditioning systems failed, and it is claimed rooftop and vertical gardens can act as thermal insulation for buildings.

The roof gardens can also help prevent flooding by sucking up water deposited as occurrences of heavy rain become more common due to climate change.

It is estimated there are about 50 green rooftops in Melbourne, and Melbourne City Council is currently mapping them.

However council environmental chair Arron Wood said sometimes they were only announced by developers as a tactic to get their projects approved.

"Don't just put these things in your planning applications and then remove them down the track," he said. "You're ultimately doing your city and customers a disservice."

A detailed Victorian guide has been recently developed for creating green roofs, walls and facades. Visit www.growinggreenguide.org for more information.

Illustration: Matt Golding. Photo: Matt Golding

Fuente: http://www.theage.com.au/victoria/extreme-gardening-on-the-92nd-floor-of-the-eureka-tower-20150323-1m45sm.html