City taxes shall be due and payable on the first day of July of each year. To all taxes paid after August 31, there shall be added a 4% penalty, and to all taxes paid after said date, there shall also be added interest at the rate of ½ of 1% for each amount or fraction of a month intervening between said date and the date of payment, or the first day of March of the next succeeding calendar year, which date shall first occur. The added penalties and interest herein provided shall be a lien against the property to which the taxes themselves apply, collectible in the same manner as the taxes to which they are added.