Any tree or shrub which overhangs any public land of the City, and which, in the opinion of the City Forester, endangers the life, health, safety or property of the public, shall be declared a public nuisance. The owner shall be notified, in writing, of the existence of the nuisance and given a reasonable time for its correction or removal as provided in Chapter 658 of the General Offenses Code. If not corrected, action shall be taken by the City Forester to abate the nuisance, and the cost shall be assessed to the owner, recoverable by suit. Such remedy shall be in addition to the penalty provided in Section 1068.99.