The Basics of Living Walls, Green Walls, and Vertical Gardens

When many people first hear the term "living wall," they think of ivy covered houses and other buildings. Though the appearance might be similar, the execution is very different.

Ivy growing up a wall is anchored in the ground. Though it may produce tendrils that grow roots into the wall, its main source of nutrients and water is still the soil at the base of the wall.

Living walls, which are also known as green walls and vertical gardens, are constructed from modular panels, each of which contains its own soil or other growing medium. This increases the variety of plants that can be used beyond the use of climbing vines.

Living walls can be either interior or exterior, and may be either a passive or an active system. (More about the distinction in a moment.)

• Living walls are extremely space efficient. Living walls make use of vertical walls - areas that would otherwise be wasted space in the garden. In small city lots, they are a perfect way to expand your garden and increase the number of plants you can grow.
• Living walls can help cut your heating and cooling bills. On exterior walls, both the growing medium and the plants themselves provide insulation and shade to the sides of buildings, cutting heating and cooling bills, in many regions significantly. Interior walls provide insulation. The insulating qualities of living walls also make excellent sound barriers to reduce street noise.
  
• Living walls can improve air quality. Both exterior and interior living walls can improve air quality. So-called "active" living walls are specifically designed to provide biofiltration and improve air quality. "Passive" living walls may or may not significantly improve air quality, depending on the choice of plants. In addition to their use as air purifiers, some active walls are also designed to reuse or purify greywater or stormwater runoff.
  
• Living walls can help cut your food bills. A number of edible plants can be grown on living walls, including many herbs, salad greens, and other vegetables and fruits.
• Living walls can provide an urban refuge for wildlife. Depending on the plants chosen, birds, butterflies, and other wildlife may visit exterior living walls.
• Living walls are beautiful. Instead of looking at the boring side of a building, you can look at a veritable explosion of greenery and flowers. Studies have shown that people whose windows look out on green spaces and other natural areas report lower stress, higher satisfaction in their job and personal lives, and other benefits.