Greenhouse Effect

Chrysanthemums don't normally bloom in summer - but they will next August in Beijing.

Inducing rainfall before clouds reach Olympic venues, authorities are now changing the time-honored blooming patterns of the city's favorite flowers to help the capital shed its "grayjing" image and be awash with color for Olympic visitors.

China's top botanical brains have been experimenting with a range of technologies like pruning and grafting to achieve this end.

"Some more advanced technologies like hormone therapy and crossbreeding have also been used," said senior horticulturist Zhang Junmin.

China has hundreds of thousands of plants - the Chrysanthemum, which usually flourishes in fall, is Beijing's official flower and boils to form a popular local tea - but many that originated here sprang to fame on foreign soil.

"China is the home of over 30,000 plants," said Zhang, a researcher at the Laboratory of Plant Tissue Culture Technology in Beijing.

"Sadly, many of the flowers that originated in China were developed into more beautiful blooming varieties in foreign countries with more advanced gardening technologies, so we have to re-import them."

His laboratory is the only one in Beijing that focuses on local flowers. It has so far attracted orders amounting to 10 percent of the total demand for the Games.

Zhang and his fellow researchers have been working on this project since 2002. Their work is important because spring and fall are the boom times for flowers in Beijing. In August, when it is hot and muggy, only about 100 varieties will grow naturally.

The lab expects to debut 11 of its 206 mutant strains during the Games.

"Chrysanthemums can't handle the Beijing summer," he said. "But our cross-breeds can."

Some 576 varieties of new plants and flowers have been discovered or bred to flourish next August, according to Xu Jia, a senior official with the Beijing Municipal Bureau of Parks and Afforestation,

"The city will be decorated with 40 million flowers," she said, adding that there are limits to how far Mother Nature will permit such meddling.

"We won't try to make the peony bloom in August, because it tends to wither quickly in the hot weather," said Xu.

China does not have a national flower but debate is now under way as to whether the peony, considered a 'royal' flower on the mainland, or the wintersweet, a symbol of persistence in Chinese culture, should get the honor.

Meanwhile, Games organizers also have to be careful not to offend local sensibilities. A patch of white flowers would be considered offensive, as this is traditionally used at funerals.

"Red, pink, yellow and orange-colored flowers are our top choices," said Xu, who will help make the selections for the Games. "My foreign customers prefer light colors and odd-looking plants like dried bamboo sticks and willow twigs," said a local flower seller in Beijing.

The problem is that all these mutant strains pose a potential threat to Beijing's ecological system, according to some local experts. Xu says no way.

"About 76 percent of the flowers that will be used for the Olympics only live for one season, so playing with their reproductive calendar will have no negative impact on the environment," she said.

When Canada Goldenrod (Latin name: Solidago Canadensis) was tagged as an invasive alien flower that squeezed out homegrown varieties with its super adaptability to almost any environment, a national campaign was launched in 2002 to eradicate the flower from the country. Now China is more careful about introducing foreign species.

About half of the flowers being "groomed" for the Olympics are indigenous to China. The rest are imports.

Xu said none of the foreign varieties are overly aggressive.

"We carefully scrutinized the flowers' culture before importing them to make sure they can't branch off and find ways of independently adapting to Beijing's climate," she said.

The Canada Goldenrod, for example, may threaten local plants in wet and balmy Southern China, but not in arid Beijing, with its freezing winters. On the contrary, it would be a welcome addition to the city if it could somehow survive the harsh conditions.

"We would happy to have them here. They are useful to prevent desertification," said Xu.

Beijing has vowed to host a Green Olympics, and this remains more important than hosting a colorful Olympics, officials stress.

The government landscaped 130,000 square meters of rooftop gardens in 2007 alone and the rate is expected to rise in coming years.

"The city will keep on investing in these green projects," said Xu.