United States Environmental protection Agency (from USEPA):
Sustainability is based on a simple principle: Everything that we need for our survival and well‐being depends, either directly or indirectly on our natural environment. Sustainability creates and maintains the conditions under which humans and nature can exist in productive harmony, that permit fulfilling the social, economic and other requirements of present and future generations.
Brundtland Commission of the United Nations 1987:
Sustainability is defined as design, construction, operations, and maintenance practices that meet the needs of the present generation without compromising the ability of future generations to meet their own needs.
Sustainable Landscaping is the work of designing, constructing, and maintaining landscapes to conserve and regenerate water, air, soil, plant, and wildlife resources, and protect and enhance human health and well‐being. Sustainable practices focus on the environment of an ecoregion while striving to be socially equitable and economically feasible.
Sustainable Landscape Practice is the use of ecologically sound principles to work in concert with natural ecoregional systems. It encourages working within closed systems with regard to organic matter and nutrient cycling. It aims to be pesticide‐free. The goal of sustainable landscape practice is to design, construct, and maintain landscapes that will continue to be aesthetically pleasing, ecologically resilient, and enduring in the ecoregion in which they are located.
ecoPRO Certified Sustainable Landscape Professionals have passed an exam that tests their knowledge of sustainable landscaping principles and best practices. They abide by the ecoPRO Code of Ethics to design, construct, and manage landscapes using the most current, ecologically sound principles and practices. Where possible, ecoPRO Certified Sustainable Landscape Professionals collaborate across the disciplines of design, construction, and maintenance.