Vertical gardens breathe new life into densely populated Asian cities

If plants can grow in the wild on a barren cliff, why not on city buildings, too, French botanist Patrick Blanc, a pioneer of the vertical garden, once mused. He began developing a prototype, and thus began the greening of some of the most densely populated urban areas on earth.

Since his original design was unveiled at the Museum of Science and Industry in Paris in 1988, Blanc's "grown up" green walls have featured worldwide, from Bahrain to Berlin, Tokyo to New York, London to Hong Kong. His projects include one of Asia's largest vertical gardens, at Hong Kong Polytechnic University's Hotel Icon - comprising more than 8,000 plants of 71 species, and completed in 2011.

In Sydney, Blanc is upping the ante, covering 1,100 square metres of the 166-metre high One Central Park tower, the first Australian project by French architect Ateliers Jean Nouvel, in a living tapestry of 23 vertical garden elements featuring 350 plant species. The tower is due for completion next year.

It is his tallest vertical garden to date, but our local architects are not to be outdone. International design practice Aedas, with its largest office in Hong Kong, is building on its green-wall portfolio of two projects already completed: at Gramercy, a 28-storey residential building on Caine Road, Mid-Levels; and 18 Kowloon East, a mixed-use tower in Kowloon Bay. In Mong Kok, Aedas is undertaking one of Asia's largest vertical gardens.

The front "face" of 78-88 Sai Yee Street, a serviced-apartment building due for completion in 2016, will feature vertical plantings 30 metres by 15 metres.

Hundreds of individual pots will be inserted into modules on a steel frame, incorporating irrigation and drainage systems for easy maintenance. The cost of the plantings will be "minimal" and the plants should last "theoretically forever", according to project designer Cary Lau King-hong, executive director of Aedas.