Stargrasses (Cynodon plectostachyus; and C. nlemfuensis Vanderyst var. nlemfuensis) and Tifton 85 (C. dactylon) are important grass for the dairy industry in Puerto Rico. Stargrasses Florona and Florico are used for grazing, while Tifton 85 is used for hay, but little information is available on new cvs. Florakirk and Jiggs. A field study was conducted in 2005 and 2006 on an acid ultisol of the corozal series (very-fine, parasesquic, isohyperthermic Typic Hapludults). Florico and Florona and Tifton 85, Florakirk and Jiggs were established in plots to assess the effects of two harvests dates (harvested every 28 d during the summer months of April to August and every 35 d from September to March of each year) on herbage mass (HM) and nutritive value [crude protein (CP), digestibility (IVOMD) and neutral detergent fiber (NDF)]. There were cultivar differences and harvest dates (P<0.05) effects on herbage mass. When harvested at 28 d, both Florona and Florico yielded over 1.2 Mg of HM per harvest than the C. dactylon cvs. Total annual HM was higher for the stargrasses (>8 Mg/ha) than the C. dactylon cvs.  Herbage mass of Florakirk and Tifton 85 HM were higher during the summer than Jiggs, but HM of Jiggs was higher than Florakirk or Tifton 85 during the September to March harvests. Crude protein, IVOMD and NDF were higher for C. dactylon cvs. than the stargrasses irrespective of harvest date.  Total annual HM of Jiggs was higher than the HM of Florakirk and Tifton 85 and is a better option for hay production in Puerto Rico.