The Director, whenever he finds and determines that the requirements set forth in Sections 13-264 or 13-265, or both, of this Subtitle have been violated, shall notify, in writing, the owner or the person responsible for the maintenance of the property to remove or properly dispose of the litter or weeds, or both, from the subject property. Such notice shall be by United States Postal Service first class mail and addressed to said owner or other responsible person at the last known address as shown on the real property tax records in the Treasurer's Office for Prince George's County or physically posted on the subject property in a conspicuous place, or personally served on an adult at the property or the owner of the property. Such notice, when so addressed and deposited with the Postal Service with proper postage prepaid, shall be deemed complete and sufficient.