No person owning or occupying any platted or unplatted lot or tract within three hundred (300) feet of a residentially zoned district or improved public right-of-way of the city shall allow the accumulation thereon of a growth of weeds, brush or grass of more than twelve (12) inches in height on vacant property or more than six (6) inches in height on any property containing a structure. This distance shall be measured along a straight line from the closest portion of the lot or tract to the closest portion of the residentially zoned property. For the purposes of this section, "residentially zoned district" is defined to include all areas zoned "R," "R-1," "R-1B," "R-2," "R-3," "P" and "T."