Dry matter yield, nutritional value and phenology of  reed  canary  grass  (<span name="style_italic">Phalaris  arundinacea</span>) were  evaluated  with  three  harvest  ages  (49, 70 and 91 days), during a year and a half, in a commercial dairy farm in the district of Santa Rosa de Oreamuno, Cartago Province. Average dry-matter yield was 3101 kg.ha<span name="style_sup">-1</span>.regrowth<span name="style_sup">-1</span> period.  Average  nutritional  value  was  17.77% CP, 55.89% NDF, 35.93% ADF, 4.14% lignin and 66.87% IVDMD on dry-matter basis. Estimated energy content  expressed  as  TDN,  DE,  ME, NEL (3X)  and  NEG   was  63.07%,  2.76,  2.13, 1.31  and  0.81  Mcal.kg<span name="style_sup">-1</span> of DM, respectively. CP fractioning of African star grass (<span name="style_italic">Cynodon nlemfuensis</span>) and perennial ryegrass (<span name="style_italic">Lolium perenne</span>), were compared with that of reed canary grass; the main contribution was obtained from the insoluble  degradable  fraction  (B2+B3)  in the temperate species, while african star grass had a higher contribution from the degradable fraction (A+B1). Average phenological stage of reed canary grass was 5.96 green leaves per regrowth and its leaf stage must be 5 to 6 leaves to optimize dry matter yield and nutritional value. Reed canary grass has been used in several dairy farms and has gained importance as an option that can withstand the weather conditions in the highlands of Costa Rica; olso, there are already companies importing sexual seed of this species), were compared with that of reed canary grass; the main contribution was obtained from the insoluble  degradable  fraction  (B2+B3)  in the temperate species, while african star grass had a higher contribution from the degradable fraction (A+B1). Average phenological stage of reed canary grass was 5.96 green leaves per regrowth and its leaf stage must be 5 to 6 leaves to optimize dry matter yield and nutritional value. Reed canary grass has been used in several dairy farms and has gained importance as an option that can withstand the weather conditions in the highlands of Costa Rica; olso, there are already companies importing sexual seed of this species

Dry matter yield; phenological stage; utilization; temperate climate grasses; Phalaris arundinacea