Green walls are essentially living systems, and therefore self-regenerating. While climbing plants have traditionally been used in buildings for centuries, modern methods using high-strength steel cables have allowed the concept to be used much more adventurously. Contemporary architecture is more convenient in many respects for the façade environmentalization of traditional buildings. With the selection of suitable species, heights of up to 25m can be achieved.
The most commonly used species for green walls or ecological walls are ivy (Hedera sp.), Russian vine (Fallopia sp.) and virginia vine (Parthenocissus sp.). Which will rise directly on the wall, especially those of brick and stone, since the porous surface allows to connect more easily, but the installation of trellises and cables can help their growth, and to some extent serve to reduce direct contact between the wall and the plant. Relatively quickly they form dense evergreen vegetation many meters high, and in many old buildings this is active management to ensure that windows and other openings are not darkened. The dense foliage provides effective nesting habitat for a variety of birds, including the Robin, Kinglet and Blackbird, as well as serving to confuse noise. A number of varieties have colored leaves, which change with the seasons, often turning red or gold during the fall.
Even in small spaces they have potential for green walls climbers, such as clematis (Clematis sp.), honeysuckle (Lonicera sp.), wisteria (Wisteria sp.), passionflower (Passiflora sp.), bougainvillea (Bougainvillea sp.) morning glory (Ipomoea sp.) and jasmine (Jasminum sp.) can be very decorative, although it usually grows slower and not as voluminous. Many have very colorful flowers that can serve as sources of nectar for insects, as well as provide a pleasant aroma.
Although it is often thought that these climbing plants can damage wall surfaces through their tendrils and adventitious rootlet feathers (in the case of ivy), in most cases, if the wall is solid and well built, there is no reason why damage occurs. Care should be taken, however, on walls with cavities with mortar or with crumbling in which the roots can take hold and expand.
The large-scale use of green walls is still a very new concept, however there is a solid research base.
Authors: Val
