Where a planned commercial development adjoins any lot in any residential zone, there shall be provided and maintained along such property line a wooden or ornamental masonry opaque fence of not less than six (6) feet in height; provided, however, that such fence shall be four (4) feet in height along the property line which bounds the front yard of adjoining residential lots. At least fifty (50) percent of such wall shall be maintained with a minimum six (6) foot wide planting strip and landscaping with trees and shrubs. (PZSC § 03-25-004)