... 2.Super thin&light 3.Waterproof&root-resistance 4.Flat irrigation system 5.Low maintaining cost Hannor wall greening system ... annual flowers. This system can be used widely, like brick wall surface, concrete walls, steel structure walls, wooden walls and etc ... choose the flexible materials, no matter its brick wall, concrete wall, wood wall, plaster wall, curtain wall, or no matter its flat or curve, ...