Trees, vines, bushes, shrubbery or flowers standing in or upon any public street or public place, or on any lot or land adjacent to any public street or public place, and having branches, limbs, trunks or other parts projecting into the public street or place shall, under the supervision of the Director of Public Works, be kept trimmed by the owner or occupant of the adjoining property so as not to interfere with the free and safe passage along such public way by pedestrians and vehicular traffic.