Any tree or shrub or part thereof growing upon private property but overhanging or interfering with public utilities or the public use of any public street, way or alley or interfering with the vision of drivers of motor vehicles using any public way, in the City, or which, in the opinion of the Director of Public Service-Safety, endangers the life, health, safety, comfort or property of the public, because of its location, the condition of its limbs, trunk or roots or because of its diseased condition, is hereby declared to be a public nuisance.