Thousands of flowers in red and yellow -- China's national colors -- will blaze across the World Expo site on China's National Day next Friday, which is also the Pavilion Day of the China Pavilion, a senior Expo organizer said.

A thousand red peonies will be planted along the 1.2-kilometer-long Expo Boulevard near the China Pavilion on Monday.

Through precise controls of temperature and humidity, they will blossom together on Tuesday, said Zhu Weifeng, deputy director of the Greenland and Park Department of the Expo bureau.

Yellow chrysanthemums will be planted among the peonies next week as well.

About 160 flower pillars and 110 flower towers which are also mainly in red and yellow are being erected, each about 2.5 meters tall --visible across the site.

The organizer said the bureau tinkered with various flowers' blooming periods by planting them in greenhouses and transplanting them to the site. The red peonies usually blossom in April, but they were frozen then to make it feel like winter. They were defrosted in August, Zhu said.

Some flowers such as the ixora, which look like clusters of red balls, were brought from south China's Fujian Province because the color resembled the China Pavilion.

New grasses that grow quickly were being planted across the World Expo site to replace those that succumbed to August's scorching sunshine and the stampede of visitors, Zhu added.