Off-street parking areas for more than five vehicles or off-street loading spaces required by this Section, shall be effectively screened on each side which adjoins or faces premises situated in any R District or institutional premises, by a masonry wall or solid fence. Such wall or fence shall be not less than four feet or more than six feet in height and shall be maintained in good condition without any advertising thereon. In lieu of such wall or fence, a strip of land not less than fifteen feet in width and landscaped with grass or evergreen ground cover and planted and maintained with an evergreen hedge or dense planting of evergreen shrubs not less than four feet nor more than six feet in height may be substituted. No wall, fence or hedge as required by this Section shall be located in a required front yard closer to the street line than the building or setback line required in the district in which it is located. Where parking areas are developed in the front yard, even though the property is located in a commercial or industrial district and the abutting or opposite properties are also the same district, a fifteen foot strip of land, landscaped with grass or evergreen ground cover and planted with shrubs or trees or both shall be provided between the street line and the parking area.