Any person owning real estate abutting upon any street or alley where tree limbs or branches extend over and above the streets, alleys or sidewalks, shall trim said trees so that the branches thereof, and the limbs thereon shall be above the sidewalks and above the street and alleys 11 feet. This section shall not require that large limbs be cut off if extending from the trunk or body of a tree over the sidewalks or streets or alleys at a less height of less than nine feet. However, that the small limbs or branches upon which the leaves or foliage appear or grow, shall be trimmed so that the small lower branches and limbs are 11 feet above the sidewalks, streets and alley.
('77 Code, § 19-1)