It is the duty of every person owning any premises in the city on which there shall be growing any fruit, shade or forest trees, or shrubbery of any kind, to keep the same free from blight, parasites, and disease, and in the event it is found that any fruit, shade or forest trees or shrubbery have become infected with said blight, parasites or other disease, it shall be unlawful for the owner of any such premises on which there shall be growing any such trees or shrubbery to fail or neglect to promptly take and use such methods as may be necessary to effectually destroy such blight, parasites or other disease or, in lieu thereof, to destroy such trees or shrubbery. (Ord. 154, § 1, 1949.)