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.

Women work on an Olympic flower bed in a Beijing suburb. [China Daily]

China's top botanical bra

ins 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.

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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.