A cool-season perennial, tall fescue (Festuca arundinacea) grows in clumps and is widely used as an animal forage during the fall and winter. During the summer and spring, the grass contains toxic alkaloids. When grown as a lawn or turfgrass, tall fescue produces year-round green color, vigorous growth, wear resistance and shade tolerance. It has spread widely throughout most of the United States and Canada, according to the Missouri Department of Conservation.
Tall fescue shares a symbiotic relationship with a fungus known as "endophyte." The fungus lives in the cells of the grass but does no damage to the host. Within the host the endophyte produces alkaloids that render the grass unpalatable to insects and nematodes. The fungus also appears to give the tall fescue increased heat and drought tolerance, according to the Southern Illinois University.
In the spring the tall fescue produces new leaf blades. At the stem of each blade the endophyte fungus develops. In May the grass begins to send out stems in preparation for reproduction. The endophyte fungus moves into the stems which helps protect them from being consumed by livestock or insects, according to the West Virginia University. On the top of each stem a seed head begins to form.
Seed Development and Dispersal
The endophyte moves from the stems of the grass into the seed heads. Once the endophyte enters the seed heads of the tall fescue seeds are produced. The endophyte enters the seeds. The wind disperses the seeds. When the seeds come into contact with the soil, germination begins. Each of the new seeds contains the endophyte fungus so the cycle begins again. After the seeds form and disperse, the tall fescue grass continues to grow into the fall.
Turf and Lawn
Tall fescue is widely grown as a turf and lawn grass. It offers exceptional wear tolerance, which makes it an ideal grass for parks and golf-courses. The grass grows rapidly and spreads using small rhizomes. The grass grows well in water-logged areas and offers drought tolerance once established. During severe drought the grass goes dormant and does not grow, according to the Texas A & M University.
Tall fescue requires frequent mowing when grown as a lawn or turf grass. It enjoys a mowing height of 2 to 3.5 inches, according to the University of Illinois. Spreading 6 to 9 pounds of tall fescue per 1,000 square feet produces a lush lawn. The grass quickly spreads when established through rhizomes. Tall fescue does not develop thatch when grown as a lawn because of its clumping ability.