(a) No person shall plant, move, trim, cut above or below ground, disturb or alter any tree or shrub in any public area of the City or within the street right of way or between a sidewalk and the street right of way, nor cause such acts to be done by others, without first obtaining a written permit therefor from the Director of Public Service, who shall issue the permit if, in his judgment, the work is necessary and the proposed methods of workmanship are of a satisfactory nature. A permit shall not be required to cultivate and water trees and shrubs.
(b) As a condition to any permit to remove a tree or shrub, the Director may require that the permittee plant one or more trees or shrubs in place of the one removed. Whenever a tree or shrub has been removed or destroyed pursuant to such conditional permit, no permittee shall fail, refuse or neglect to plant another tree or shrub or other trees or shrubs of the type and size and at the location specified in the permit within the time specified by the Director from the date of the issuance of the permit.