Transition requirements—Where a drive-in restaurant or fast food restaurant is proposed to abut a residential zone, a buffer area of a minimum of fifteen (15) feet in width shall be established along the common lot line of the adjoining residential use or residential zone, whichever the case. The buffer area shall be landscaped with deciduous and coniferous trees to provide a year-round visual screen from the drive-in restaurant or fast food restaurant site to adjoining property. Tree plantings shall be a minimum of four (4) feet in height.