Maintain all landscape vegetation, including, but not limited to, conifers (e.g., cedar, cypress, fir, juniper, and pine), eucalyptus, acacia, palm and pampas grass in such a condition as not to provide an available fuel supply to augment the spread or intensity of a fire. The Notice of Noncompliance citing violations of this subsection will specify that such landscape vegetation poses a threat to buildings or structures in the vicinity and may cause them to be indefensible, and shall describe the work required to be done.