The growth of high-rise gardens: Let a thousand rooftops bloom

A dazzling horticultural revolution is breaking out over south-east Asia, as cities discover the many benefits that gardens can bring to the 21st-century urban environment. Clifford Coonan reports

Branches laden with lemons and lychees, the fruit trees thrive in the unlikely setting of a small balcony on the 30th floor of one of Hong Kong's high-rise gardens. In crowded public housing estates in Singapore, cucumbers and lettuces are growing in rough wooden boxes in concrete yards under fluorescent light. And Chinese schoolchildren enjoy an afternoon out with their parents not far from the Great Wall near Beijing, planting some of the millions of trees that are keeping the desert at bay and making the air easier to breathe.

Asia's green-fingered enthusiasts are leading a revolution that sets out to combat CO2 emissions, provide a bit of colour and bring the scent of flowers into people's lives.

Although most south-east and east Asian apartments do not have enough room to swing a watering can, and the tough pace of life makes it difficult to find time to cultivate even a little window box, gardening is booming.

Governments are slowly waking up to the idea that gardeners can be good for a city. Plants cut air and noise pollution, they reduce air temperatures and, as office workers sheltering from the searing lunch-time heat in a Hong Kong park can attest, they provide shade.

Hong Kong exemplifies the rise of the tower block in Asia. The green mountainsides of the island and the relatively undeveloped parts of Kowloon gave way in the 1950s and 1960s to low-rise, then high-rise residences. Gardening became something the elite on Victoria Peak did on weekends, but was not an option for the poor workers of Mong Kok or Causeway Bay.

A surgeon called Arthur van Langenberg has become the poet laureate and brave champion of urban gardening - and is on a mission to show that living in Hong Kong does not mean abandoning your connection to nature. He was surprised to discover there was no manual on how to garden in the city, so in 1983 he published Urban Gardening for Hong Kong. In 2005 he published a follow-up called Urban Gardening: A Hong Kong Gardener's Journal. Dr van Langenberg's works look at some of the challenges of gardening in a high-rise environment. Some avowed enemies include birds, dogs, cats and sceptical neighbours. His own simple beginnings commenced with "flower pots on window sills, wooden packing crates in verandahs, dragon urns at entrances, eventually graduating to a small garden".

These days, Dr van Langenberg has avocado, papaya and lemon trees growing in the concrete yard of his apartment near the city centre.

Singapore is known as the Garden City, and is famous for its orchids. One of its landmarks is the Esplanade, in the shape of a giant durian fruit. Singapore's tropical climate and clean environment make it perfect for gardening. However, the dizzying pace of growth means there is a shortage of gardens, largely because four-fifths of Singapore's 4.5 million people live in tower blocks, built by the Housing Development Board.

This is hard for the Singaporean soul, which is deeply engrained with the notion of growing things. Wilson Wong, 28, started the Green Culture website in September 2004, which provides information for local horticulturalists.

"The first plant that I grew was perhaps the beansprout, which was featured in the primary school science curriculum then. Along the way, I grew and killed houseplants such as various cacti and succulents from Holland," he says on the website. "The idea came about when I was resuming my national service soon after graduation from university in the third quarter of 2004. Perhaps I was too free then but it could also be due to the lack of directions after the sudden release from all school commitments," he said. "I felt a strong sense to go back to my gardening roots then. I felt happier and fulfilled to do gardening," he said.

The website has helped Mr Wong to develop his own skills, allowing him to grow plants under fluorescent lights and even start to cultivate flowers, the first one being the flame violet (Episcia), as well as learn the basics of landscaping and about outdoor plants. The website forum has attracted more than 1,500 high-rise gardeners in Singapore, seeking advice and looking to track down seeds, swap plant cuttings and generally enjoy the community of other green-fingered enthusiasts. Late last year, he started a community garden near his home.

Last month Singapore unveiled Treelodge@Punggol, its first "green" housing estate. Plants growing on the walls keep the 712 apartments inside the seven 16-storey tower blocks cool and pleasant. On top is an eco-deck, a large garden with a jogging track and exercise stations.

Mr Wong said his goal was to "bring gardening to the masses" - a message with a similar ring to the one in mainland China. If small moves to bring about environmental change in Asia are to have any effect, then they have to be a success in China. The precedents are there. A Chinese garden was traditionally a peaceful place of contemplation. But these days the traditional Chinese garden survives principally in the names given to the huge housing developments or plush villas springing up all over the cities and suburbs - River Gardens, Beijing Legend Garden or King Garden Villa. However, people are increasingly getting out on to their roofs.

People mostly grow vegetables but increasingly they are using their balconies to grow flowers and small trees. Beijing has pledged to add 100,000 square metres of roof gardens every year from 2007-10. For many years flowers were considered a bourgeois obsession, but horticultural shows are all the rage in China these days, and cities compete for who can stage the most spectacular. Shenyang in the north-east hosts a fabulous display of horticultural prowess with its flower show. Yan Hongwei, professor of forestry studies at the city's Agricultural University, believes China needs more garden designers to improve its urban environment.

While green belt areas in China's cities are eight times larger than they were 20 years ago, more talent is needed to better design the green areas.

China has five million gardening workers, but most of them are unqualified, and this needs to be improved, the officials say. Gardening takes on huge proportions in China. In April, President Hu Jintao and Premier Wen Jiabao joined two million people in Beijing for voluntary tree planting outside the city. "Forestation is a matter that concerns the immediate interests of the people. Every citizen should assume his responsibility and actively participate in planting trees," President Hu told the volunteers. The government is keen to plant more trees before the Olympic Games in Beijing next year to help break down pollution and stop dust from the Gobi desert choking the dry city during the summer. The city plans to plant 510,000 trees in the Olympic Forest Park near the Olympic stadium.

In 1981, the government declared that all Chinese citizens aged from 11 to 55 were required to plant three to five trees every year. Last year, about 550 million Chinese planted 2.16 billion trees, according to statistics from State Forestry Administration.

China is taking to horticulture in true revolutionary fashion. Its international image tarnished by the prospect of becoming the world's biggest emitter of CO2, the government is organising a Green Long March which will wend its way across China in July to underline the country's commitment to environmental sustainability. More than 10,000 students and environmental activists will march along 10 routes across China, teaching good green practice and planting trees. It will be led by Beijing Forestry University with 43 colleges across China co-operating, covering thousands of miles in 20 provinces and 500 cities. The Long March in 1934-36 was a deeply red affair, as the Great Helmsman Mao Zedong led 86,000 Communists on a huge trek across China to escape the Nationalist forces.

Professor Qian Jun, vice-president and vice-party secretary of Beijing Forestry University, called for the trek "to reflect the seed planting" role of the original Long March, where Green Long March members would promote conservation.

The Long March remains a focus for intense national pride in China, something the organisers of the Green Long March hope to harness to improve the country's woeful environmental record. Most of the world's dirtiest cities are in China, while rivers like the Yangtze are in danger of dying out.

The Green Long March will also accentuate the positive schemes that are already in place. The aim of the trek is to raise awareness, teach communities about environmentally responsible development and bring together scattered conservation efforts, such as the use of solar panels in Tibet, or eco-friendly vegetable growth in Shanghai, or sustainable farming in Sichuan province.

Given the success of the original trek, perhaps the new Long March could bring about a Green Revolution.