Li Haigen, 57, who moved to Shanghai about eight years ago, not only helped the American participants turn their blueprint into reality, he also made some changes to make the work more striking.

The sculpture, known as Rodeo, features three running horses and two bulls. The work is submitted by the city of Rotan in Texas. The Americans mailed five sketches of rodeo movements to the organizing committee. The committee passed on the designs to Li to turn into plant sculptures.

"They gave me enough freedom to make my own creation," said Li, who was allowed to choose the size and type of plants used in the work.

In two designs, the horses' front feet were supported by steel poles. But he thought the supports would lessen the impact of the work. "So I thought about using physics to set them free," said Li.

With a background in architecture, Li designed a special sculpture frame. The interior structure is made with small triangular components to keep balance, and allow the two-ton sculpture to stand on its own.

"I found the result very satisfactory."

Now, Li's assistants are busy covering the sculptures with ornamental greenery and putting the final touches on them for the show's opening on September 5.

The show, to run through November 30, will feature the work of artists from 24 countries and regions.

"I worked on plant sculptures before," said Li. "But probably this is the most difficult piece I've ever created."

Li's interests in gardening only started in the late 1970s. He worked before as an airplane engineer in Chengdu, Sichuan Province. But he was posted to the greenery department during the Culture Revolution (1966-1976).

"I was told to supervise the greenbelts in Chengdu. I found I really liked the job, though it had nothing to do with my previous one." So the career change allowed Li to realize where his real passion lies.

Shanghai Century Park
Location: eastern end of Pudong Shiji Dadao
Ticket: RMB 15 per person
Tel: 010-38760588