It is unlawful for any person having the control, possession or ownership of any lot or block of land within the limits of the city to permit or allow the sidewalk in front of the lot or block of land to become obstructed by weeds, grass or other vegetable growth in such a manner as to deface the sidewalk, thereby impeding travel or menacing the public safety in the matter of fire. (Ord. 22 CS §§1, 2; prior code §16.6.)