Vertical Garden

Patrick BLANC

Oasis d' Aboukir, Paris

The core innovation is to use the root ability of the plants to grow not only in a volume of soil but also on a surface.

Biodiversity in Urban Architecture

Whenever roots are allowed to grow deep inside a man-made wall, they can easily damage the wall and cause its destruction. This rootrelated damage can be excluded if the Vertical Garden is totally insulated from the existing wall. The Vertical Garden becomes a second skin of the building and this is a living skin. The plant roots are then only spreading on the surface of the Vertical Garden structure, leaving the inner wall unaffected. Plants and architecture can thus cope with harmony.

The core innovation is to use the root ability of the plants to grow not only in a volume of soil but also on a surface; this is just what they do in their natural environment when their roots are growing on tree barks or among the mosses covering the rocks. Without any heavy soil, the plant-supporting system is very light and thus can be implemented on any wall, whatever its size. The Vertical Garden can be set up both outdoor and indoor. Of course, the plant species selection is set according to the prevailing climatic conditions.

The Vertical Garden is composed of three parts: a metal frame, a PVC layer and a layer of felt. The metal frame is hung on a wall or can be self-standing. It provides an air layer acting as a very efficient thermic and phonic insulation system. A 1 cm thick PVC sheet is riveted to the metal frame. This layer brings rigidity to the whole structure and makes it waterproof. A felt layer, made of polyamide, is stapled on the PVC. This felt is rotproof and its high capillarity allows a homogeneous water distribution.

The roots grow on and inside this felt. Plants are installed on this felt layer as seeds, cuttings or already grown plants. The whole weight of the Vertical Garden, including plants and metal frame, is lower than 30 kg per square meter. Thus, the Vertical Garden can be implemented on any wall, without any size or height limitation.

Thanks to its thermic insulation effect, the Vertical Garden is very efficient and aids in lowering energy consumption, both in winter (by protecting the building from the cold) and in summer (by providing a natural cooling system). The Vertical Garden is also an efficient way to clean up the air. In addition to leaves and their well-known air-improving effect, the roots and all the micro-organisms related to them are acting as a wide air-cleaning ecosystem. On the felt, polluting particles are taken in from the air and are slowly decomposed and mineralised before ending up as plant fertiliser. The Vertical Garden is thus an efficient tool for air and water remediation wherever flat surfaces are already extensively used by human activities.