As the world's population increases and cities become denser, the demand and popularity of vertical gardens is on the rise.

The concept of a vertical garden is not a new one, however with increased urbanisation, the benefits of vertical gardens and green walls are becoming significantly more important.

Here we look at six of the world's best vertical gardens:

Tree House - Singapore

Standing 24 storey's tall in Bukit Timah, Singapore, Tree House is a recently completed condominium developed by City Developments Limited.

The two vertical gardens on the facade of the apartment building span 2,289 square metres, making it the largest vertical garden in the world according to The Guinness World Records.

The development, which also features heat reducing windows and motion sensor lighting is expected to save more than $500,000 in energy and water savings annually.

 
Central Park - Sydney

Designed by Patrick Blanc, One Central Park features 23 green walls comprising of 35,000 wall plants and 85,000 facade plants. With an area of approximately 1,200 square metres, One Central Park was in contention for the Guinness World Record until Tree House took the top spot.

The vegetation is made up of over 350 different species of plants, most of which are native species to withstand the Australian climate.
Related Article: Frasers Property’s Central Park Awarded Three Green Star Ratings

Centro Commerciale Fiordaliso - Rozzano Italy

This shopping centre not far from Milan boasts a vertical garden with a colourful array of more than 44,000 types of mosses and plants over an area of 1,263 square metres. Designed by architect Francesco Bollani, the total cost of this project was 1 million euros ($1.3m). The garden assists with regulating the temperature inside the shopping centre by reducing sunlight. It is also said to reduce ambient nose and carbon emissions from the car park traffic.

 
Rubens Hotel - London

Located in the heart of London, just a stones throw away from Buckingham Palace lies Rubens Hotel featuring London's largest vertical garden.

Designed by Gary Grant of Green Roof Consultancy, this garden covers an area of 350 square metres with over 10,000 plants. Serving more than just an aesthetic purpose, it is also designed for flood mitigation purposes. The rooftop of Rubens Hotel captures rain water to then be stored in tanks with a capacity of 10,000 litres, which can also be used as a means of irrigation to the 16 tons of soil housing the vegetation.

 
CaixaForum - Madrid

This old power station-turned-modern art gallery features a vertical garden almost 600 square metres in size. Designer Patrick Blanc chose nearly 300 different plant species and a total of 15,000 plants to make this sculptural piece of art, fitting for a gallery.

The Currents - Quebec

Unlike the above mentioned gardens, The Currents consists of a vertical garden within the interior of the building. Inside the Desjardins building in Levis, Quebec stands a 65 metre vertical garden which covers an area of almost 200 square metres. Design firm Green Over Grey took five months to design the wall, incorporating 42 different plant species found in similar vertical locations in nature. The wall is completely hydroponic, meaning soil is not required for the plants to prosper.

Two upcoming vertical gardens to look out for in the near future:

Bosco Verticale in Milan