Condition of property. All open portions of any developed lot operating under a special use permit shall have adequate grading and drainage and shall be continuously maintained in a dust-free and erosion-resistant condition by suitable landscaping with trees, shrubs, grasses or other planted ground cover or by paving with asphalt, concrete, washed stone or other suitable material. Required yard areas shall be planted and maintained in accordance with the approved site plan for the premises and in a manner that is compatible with its use and beneficial enjoyment. Unpaved parts of the site shall be maintained in grass and landscaped, including any such property that may be in a street, rail, or utility right-of-way. Maintenance of individual building sites shall be the responsibility of the occupant and/or owner. The premises, buildings, and all improvements shall be kept in a safe, clean, healthful, and presentable condition at all times. The removal of undergrowth, weeds, debris, rubbish, trash, excess dirt, industrial wastes or garbage, and any other unsightly material from a building site shall be done or arranged to be done by the occupant and/or owner.