A new and distinct plum tree variety, Prunus salicina, cv. ‘Suplumfiftythree’ is characterized by having large, juicy fruit with black skin and red flesh. The fruit of the new variety ‘Suplumfiftythree’ also has a high Brix:Acid ratio, firm flesh, a mild sweet flavor and a stone that clings to the flesh. The date of ripening of the fruit of the new variety is later than for ‘Black Splendor’ (unpatented) and earlier than ‘Owen-T’ (unpatented). The fruit of the new variety ‘Suplumfiftythree’ is larger than the fruit of ‘Black Splendor’ and smaller than the fruit of ‘Owen-T’.
