The International Horticultural Exposition opened in the coastal city of Qingdao in east China's Shandong Province on Friday.

The following is a review of major international horticultural events held in China's mainland since 1999. The events are recognized by the International Association of Horticultural Producers (AIPH).

World Horticultural Exposition, Kunming, 1999

China's southwestern Kunming City, provincial capital of Yunnan Province, opened the International Garden Festival on April 30, 1999. It was the first such event hosted by China. The expo ended on Oct. 31, attracting 9.5 million visitors. All the pavilions built for the event were preserved after the expo closed. It also promoted the development of tourism, business and trade in Yunnan.

China International Horticultural Exposition, Shenyang, 2006

China's northeastern Shenyang City, provincial capital of Liaoning Province, opened the expo on April 30, the second time the country hosted such a gardening event. The expo ended on Oct. 31 and attracted 12.6 million visitors. The event helped promote the city and Liaoning at home and abroad, and created business opportunities.

China International Horticultural Exposition, Xi'an, 2011

China's northwestern ancient Xi'an City, known as Chang'an in ancient Chinese history, opened the expo on April 28. It was the third mainland city in China to host such an event. The event concluded on Oct. 22 and attracted 12 million visitors. The expo helped promote the ancient city and Shaanxi Province at home and abroad, and created business opportunities.

China International Horticultural Exposition, Qingdao, 2014

It is the fourth mainland city to host such an event.

The flower and gardening expo is expected to boost public awareness of ecological protection and economic development.

During the expo, marine plants brought back by Jiaolong, China's first manned-submersible, and plants cultivated from seeds brought back by Shenzhou spacecraft will be displayed in the 241-hectare park. The event is expected to attract 12 million visitors.

The AIPH is a coordinating body representing horticultural producers' organizations all over the world. It was set up in Switzerland in 1948 to stimulate international marketing of flowers, plants and landscaping services. China's AIPH membership began in 1994. Beijing will stage the exposition in 2019.