In the west, ancient Egyptian courtyards, ancient Greek and Roman gardens, grapes, roses and ivy were arranged into verandas. In recent years, with the speeding up of world city modernization, the urban construction land and green land of contradictions increasingly prominent, people had to begin to pay close attention to the development of the urban green space, as urban roof greening boom at the same time, the arrival of people gradually focused on containing the huge green space of city buildings on metope.
In some developed countries, the use of plants to "build walls," in some villas in the United States also use plant walls to separate rooms. In Brazil, there is a kind of "green grass wall", which is made of hollow bricks filled with soil and grass seeds. The grass grows into a green wall. In Japan, plant systems such as lawns, flowers or shrubs are installed on walls, guardrails, sloping walls and vertical advertising supports, turning concrete into green forests.
There is also an ornamental wall above the garden plants, cultivation mechanism and fixed devices form a complete section, this green wall can be used both outdoor and indoor. The wall of life, which is 150 meters long and more than 12 meters high, is displayed at the 2005 aichi expo in Japan.
Beijing, Shanghai and chongqing are well implemented, among which Shanghai has the best development. The 2010 Shanghai world expo is themed on "better city, better life". According to statistics, more than 80% of the nearly 240 expo venues in Shanghai world expo have been vertically greening, including roof greening and wall greening.
According to incomplete statistics, the total length of the walls of public units in China is more than 5 million kilometers, which can circle the earth 125 times, covering an area of more than 1,100 square meters. In addition, the unusable dead Angle on both sides of the walls and the outer wall of buildings that can be greened up to 10,000 square kilometers, showing that the development potential of wall greening is quite huge.