It shall be the duty of the City inspectors to make careful examination and investigation as may be provided hereunder for the growth and spread of injurious and noxious weeds, and of garbage, refuse or unsightly or deleterious objects or structures; and it shall be the inspectors’ duty to ascertain the names of the owners and the descriptions of the premises where such weeds, garbage, refuse, objects or structures exist and to serve notice in writing upon the owner and/or occupant of such land, either personally or by mailing notice, postage prepaid, addressed to the owner or occupant at the last known post office address as disclosed by the records of the county assessor, requiring such owner or occupant, as the case may be, to eradicate, or destroy and remove, the same within such time as the inspector may designate, which shall not be less than ten (10) days from the date of service of such notice. One (1) notice shall be deemed sufficient on any lot or parcel of property for the entire season of weed growth during that calendar year. The inspectors shall make proof of service of such notice under oath, in the manner hereinafter set forth.