Along lot lines other than street lines within said buffer area, a solid and continuous screen shall be planted and maintained. Said landscaping shall consist of massed evergreen and deciduous trees and shrubs of such species and size as will produce, within two growing seasons, a screen of at least eight feet in height. Such screen shall consist of a minimum of double row of staggered plant materials planted 10 feet on center and staggered or parallel, serpentine, or broken rows as approved by the municipal agency.