Timothy grass (Phleum pratense) is a cool-season perennial grass from temperate regions. It grows in erect culms 50 cm to 1 m tall (sometimes up to 1.3 m) (AWI et al., 2012; FAO, 2013). It has a shallow, fibrous root system (AWI et al., 2012). Its lower internodes remain short and become enlarged, forming a bulb (haplocorm, corm, bulblet) that serves as a storage organ for carbohydrate reserves. Individual shoots live during parts of two growing seasons, and some new shoots develop each year from older ones, which results in a perennial stand (Lacefield et al., 1980). The leaves are smooth and hairless, pale green to greyish-green. They are rolled when young and become flat and pointed, slightly rough on the margin, rather large (3-10 mm) and long (up 30-45 cm) (FAO, 2013; AWI et al., 2012). The seed heads are dense cylindrical spikes up to 15 cm in length. The seeds are very small, with approximately 3 million seeds per kg (AWI et al., 2012). A characteristic of timothy grass is its fast growth relative to other grasses, which enables it to accumulate quite a lot of standing biomass before senescence appears (FAO, 2013). However, this fast maturity means that the harvest window for optimal quality is narrower than for other grasses (Bernes et al., 2008).