Any portion of the site not used for buildings, structures, parking compounds, loading areas and sidewalks shall be maintained with a vegetative ground cover and other ornamental plantings. A minimum ten-foot-wide landscape strip shall be provided along all front and rear lot lines. A minimum five-foot-wide landscape strip shall be provided along a side lot line, except when joint parking facilities are shared by adjoining uses, this side yard landscape strip can be waived for that portion of the site occupied by the joint parking lot. (See Article XXVI.)