All areas between such buildings or structures and a public street and property in any R Zone located off-site, except for walkways, parking spaces and driveways, shall be landscaped and permanently maintained including a continuous row of evergreen, vertical landscaping in sufficient quantities to provide a visual buffer screen between mausoleums and columbariums and adjacent off-site properties. The type, number, size, and location of coniferous and deciduous tree species for the visual buffer screen shall be approved by the Planning Director. Provided, however, if such areas are used for off-street parking of automobiles there shall be a strip of land not less than five feet in width surrounding such off-street parking areas, except for walkways and driveways, which shall be landscaped and permanently maintained.