Installed plant materials shall meet the standards in the most recent edition of the American Standard for Nursery Stock (ANSI Z60.1), published by the American Nursery and Landscape Association. All required landscape areas soils shall extend to the native soil. Plant materials shall be properly supported to ensure survival. Support devices such as guy wires or stakes shall not interfere with vehicular or pedestrian movement. Maintenance of landscaped areas is the ongoing responsibility of the property owner. All landscaping shall be installed and maintained to protect it from vehicular damage through the use of curbing and to provide adequate vision clearance. Required shrubs and trees shall not be pruned or sheared below their code-required spread or height.