Carpet greening planting all kinds of ground cover plants, if patterned, the effect is better. For example, Shanghai Academy of Agricultural Sciences has successfully developed a "one-step roof greening technology" suitable for light flat roof greening. This technology has obtained the national intellectual property patent and passed the certification of Shanghai high-tech transformation project. It has an application area of over 50,000 square meters in Shanghai and Beijing, and is the largest roof greening promotion project in Shanghai and Beijing.
This technology selects Sedum sarmentosum of Sedum family, which has short meat quality, creeping growth, branching on nodes, self-propagation, extreme drought resistance, cold resistance, barren resistance, green in winter, green in spring, water and labor saving, and almost no management is needed. Lawn blocks cultivated in the base with 2 ~ 3 cm thick matrix materials can be planted on the roof at one time. Compared with the roof treatment methods such as painting, laying plastic sheets (mats) and changing slopes, the cost is lower. Experts and the media say that this Sedum is the best plant for roof greening at present.
Secondly, for the roof with strong bearing capacity, garden greening with trees and shrubs should be planted. This method is suitable for large roofs, mostly used in high-end hotels, guesthouses and high-rise buildings, which makes the roof space change greatly and produces colorful effects. For example, a rooftop garden on the east side of Hangzhou Wulin Square was built on the roofs of two three-story buildings and connected by arch bridges. There is a football field and more than 50 kinds of flowers and trees are planted in the garden. All the year round is like spring, which is several times higher around it.
The third is combination, that is, free placement, mainly in the four corners of the roof and the side of the load-bearing wall with potted plants to decorate the roof greening, which is more flexible. Which way to choose depends on the load of the roof, the location of the load-bearing wall, the flow of people, the surrounding environment, the use and so on. Scaffolding greening is used to plant vines, such as grapes and kiwifruit, because the cultivation substrate and scaffolding columns can be placed on the load-bearing wall, and the load of scaffolding and plants is small. This greening method has less load on the roof, which can be borne by ordinary roof structures, and is especially suitable for the roof of low podium in front of high-rise buildings. For example, sweet potatoes, peppers and flowers are planted on the roofs of some buildings in Chongqing; Some roofs in Chengdu have not only planted flowers, but also built nurseries, medicine nurseries and melon gardens. The green roof area exceeds 6,543,800 square meters, and there are hundreds of roof gardens, with a larger garden area of 2,000 square meters.