It grows to tall, with leaves up to long and broad. The leaves are hairless, rolled rather than folded, and the lower sheaths turn dark brown. It has no stolons or rhizomes, and no auricles. The flowerhead is long and broad, with densely packed spikelets. It flowers from June until September. The stamen are pink. The ligule is short and blunt. It grows well in heavy soil, and is noted for its resistance to cold and drought, and thus ability to grow in dry upland or poor sandy soils. In pasture it tends to be overwhelmed by more competitive grasses. After cutting it grows slowly.
Subspecies
There are two subspecies:
Phleum pratense subsp. pratense. Larger, to tall. Widespread.
Phleum pratense subsp. bertolonii. Smaller, to tall. Calcareous grassland.
Cultivation and uses
Timothy grass was unintentionally introduced to North America by early settlers, and was first described in 1711 by John Hurd from plants growing in New Hampshire. Hurd named the grass "hurd grass" but a farmer named Timothy Hanson began to promote cultivation of it as a hay about 1720, and the grass has been known by its present name since then. Timothy has now become naturalized throughout most of the US and Canada. It is commonly grown for cattle feed and, in particular, as hay for horses. It is relatively high in fibre, especially when cut late. It is considered a harsh, coarse grass little relished by livestock if cut earlier. It is considered part of the standard mix for grass hay and provides quality nutrition for horses. Timothy hay is a staple food for domestic pet rabbits, guinea pigs, chinchillas, and degus, often making up the bulk of their diet. Timothy hay is rich in long fibre and its abrasive texture helps to grind down the teeth, keeping both the teeth and jaw in good order. Some caterpillars use it as a food plant, e.g. the Essex skipper and the marbled white. It also grows in roadsides and abandoned fields but generally requires nutrient-rich soils. Its pollen is a common allergen; it has recently been used in small amounts as part of a new hay fever vaccine Grazax, which is designed to recondition the body's immune system so it no longer responds to pollen. Plants persist through the winter. Dead, straw-colored flowering stems may persist, but only for a short time, and are recognized by the distinctive spike-like inflorescence.
Confusion with other species
It is often confused with meadow foxtail. Timothy flowers later, from June until August, whereas meadow foxtail flowers from April until June. The spikelets of timothy are twin hornlike projections arranged in cylindrical panicles, whereas foxtail has a soft, single awn. Purple-stem cat's-tail prefers lighter soils and grows on chalk downland. Mountain timothy grows above 6,000 feet. A "wild Timothy" was found to grow in Yosemite at the time of its discovery but may have been a foxtail. Timothy canary grass, another species with a similar cylindrical panicle, is toxic to livestock.
