What is a a green wall? As defined by wikipedia: "A green wall is a wall, either free-standing or part of a building, that is partially or completely covered with vegetation and, in some cases, soil or an inorganic growing medium. The creator of a large green walls concept (vertical gardens) is the French botanist Patrick Blanc. The vegetation for a green façade is always attached on outside walls; with living walls this is also usually the case, although some living walls can also be green walls for interior use] For living walls there are many methods including attaching to the air return of the building to help with air filtration. They are also referred to as living walls, biowalls, vertical gardens or more scientifically VCWV (Vertical Vegetated Complex Walls).
There are two main categories of green walls: green façades and living walls. Green façades are made up of climbing plants either growing directly on a wall or, more recently, specially designed supporting structures. The plant shoot system grows up the side of the building while being rooted in the ground. With a living wall the modular panels are often made of stainless steel containers, geotextiles, irrigation systems, a growing medium and vegetation".