Although there are many commonalities between designing interior and exterior rooms, one significant difference is that the exterior space exists in the outdoor environment where natural elements and processes are constantly present. A residential site is a living entity composed of abundant organisms including trees, shrubs, annuals, perennials, lawn, and even miniature flora such as moss and lichens. In addition, the residential site is a habitat for various animals, birds, and insects that live, feed, and nest in the ground, in woody and herbaceous plants, and in the tree canopies above. Less obvious to the eye are millions of microorganisms that exist in the air, plants, and soil. Collectively, these living organisms form an interconnected web of life embracing the entire residential landscape.
A range of natural processes such as growth, decay, sun, wind, precipitation, runoff, and fire collectively affect the presence and health of the various life forms on the residential site. These ever-present forces provide the necessary ingredients for life to exist, though they can be devastating when there is too much or too little of any of them. The natural forces likewise animate the landscape as they touch, move through, or seasonally alter every aspect of the outdoor environment.
All in all, the residential landscape is a living, dynamic setting that is constantly evolving and should be designed and managed as such. Proper residential design must promote the health of all living organisms on a site and be responsive to the natural forces that are always present. Accomplished design should also be considerate of the larger environmental issues affecting the region, country, and world. This approach to landscape design is commonly known as sustainable design. This chapter examines what sustainable landscape design is and presents numerous design and management strategies for making a residential site environmentally fit.