The city shall have the right to plant, prune, maintain and remove trees, plants and shrubs within the lines of all streets, alleys, avenues, lanes, squares and public grounds, as may be necessary to ensure public safety or to preserve or enhance the symmetry and beauty of such public grounds. The commission may remove, or cause or order to be removed, any tree or part thereof which is in an unsafe condition or which by reason of nature is injurious to sewers, sidewalks, electric power lines, gas lines, water lines or other public improvements, or is affected by any injurious insect, pest or disease. This section does not prohibit the planting of street trees by adjacent property owners; provided, that the selection and location of said trees is in accordance with sections 7-5-3 through 7-5-5 of this chapter. (1991 Code § 12.16.090, as amended)