No person shall plant any shade or ornamental tree, plant or shrub in any public highway or park until the Superintendent of Public Works has approved the kind, size and variety of the same and designated the location for planting the same. The Superintendent shall not approve the planting of and no person shall plant any tree upon any street or highway, except under the following conditions:
(a) Such tree is one of the following varieties: green ash, althea, American elm, birch, Norway maple, column linden, sycamore maple, hornbeam, sweetgum, oak, flowering crabapple, flowering plum and ginkgo.
(b) Such tree is not less than forty-five feet from every other tree, unless it is an American elm, which shall not be less than sixty feet from every other tree.
(c) Such tree is free from infectious disease.
(d) Such tree, when planted, has a diameter of at least one inch at a distance of one foot above the ground level.
(1979 Code Sec. 13.40.020)