Knowing the proper sowing and harvesting periods in plants cultivated as roughage resource is very important for achieving high yield and quality performance. However, studies on sowing and harvesting times in quinoa grown for hay production are almost non-existent. In this study, the effects of different sowing (middle of March, end of March, beginning of April and middle of April) and harvesting (the end of vegetative stage, beginning of the flowering and the full flowering) periods on herbage yield and quality performance of quinoa’s Mint Vanilla variety were investigated. Research was conducted under irrigated conditions of Igdir during 2017-2018. The experimental design was split plot design with three replications. According to statistical analysis, higher plant height, dry matter and crude protein yields were obtained from plants sown at the end of March and harvested at full flowering. The highest crude protein ratio, dry matter digestible and relative feed value with the lowest neutral detergent fibre and acid detergent fibre ratios were observed in plants sown in the late period and harvested at the early period. As a result, crude protein and digestibility values were generally increased while dry matter and crude protein yields were decreased with late sowing and harvesting.