What Causes Tall Fescue Grass?

Tall Fescue

• Tall fescue (Festuca arundinacea) is a perennial bunch grass that produces seeds and rhizomes. It is a deeply rooted grass that tolerates both floods and droughts. It adapts easily and readily to a variety of soil conditions, but prefers soils with a pH level between 5.8 and 6.5. This vigorous grass is useful in preventing soil erosion, and farmers often grow it for livestock feed. Unfortunately, its aggressive habits and tall growth make it an unwelcome visitor in established yards and landscapes.

Disbursement

• Like other types of wild grass seed, tall fescue can make its way into your lawn in a number of ways. Wind and animals can spread the seeds to other areas. While a thick, strong growth of lawn usually discourages the growth of rogue weed and grass seeds, bare patches can provide the ideal opportunity for new seeds to sprout and grow. Compost and soil amendments can also cause tall fescue grass to appear in your lawn. Treating your soil with vegetative amendments, such as grass clippings, shredded straw and cow manure, can introduce tall fescue into your manicured yard.

Problems

• While tall fescue is useful for livestock forage and grazing, it can look weedy in lawns. The blades grow quickly to reach a mature height around 2 feet tall, making them stand out sharply in a manicured lawn. Even after mowing, the broad blades and clumps can deter from the refined appearance of a uniform expanse of healthy lawn grass. Tall fescue is commonly a host plant for a type of fungus called Acremonium coenophialum. While the fungus has little effect on the tall fescue, it may spread and damage other types of lawn grasses.

Removal

• Selective herbicides are useful in controlling and killing tall fescue grass in lawns. Select an herbicide labeled for use with your type of lawn grass and apply it according to the manufacturer's instructions. Keeping your lawn grass healthy will help it ward off weed and grass invasions. Re-seed any bare patches with lawn grass seed to minimize the growth of tall fescue grass and weeds.