Fescue is a cool-weather grass found in low, damp areas with poor aeration. Fescue has deep roots and can grow in weather that other grasses can't, making it a problem during the winter months and during drought conditions. Killing of fescue grass keeps it from forming a dense mat that chokes off the rest of your lawn.
Not only does fescue choke off other plants, but it also produces harmful compounds that affect and lower the amount of germination other plants in the surrounding area can produce. This kills off varieties of plants and makes it hard for wildlife in the area to find food.
If you wish to keep fescue around in the yard for its resistance to heat, drought, or cold weather, you should keep it mowed to a length of 1.5 inches or more. Tall fescue will burn in high heat if mowed too low. During the winter, you can let it grow.
The use of herbicides is an effective control for tall fescue grass. Herbicides will usually kill fescue with the first application, allowing for the fast growth of healthy, non-intrusive grass. Spraying should be done during the active growing period of March to April, or September to October. Before application of herbicides, the fescue should be mowed, burned or grazed and allowed the chance to regrow to a height of 6 to 12 inches. This ensures new growth takes the full amount of herbicide.
Tilling the earth the fescue is growing in can also prevent further growth. Tilling is only recommended in areas where the earth is of a non-erosive quality. Work the soil in the spring as soon as it has been given a chance to defrost. Allow the soil to germinate and then till the top 2 to 3 inches of soil to eradicate fescue.
If you wish to keep fescue grass in your lawn, keep it watered regularly. Allow the grass to dry to the point where it needs water, then wet the soil so that it is soaked to a depth of 3 to 4 inches. Tall fescue requires a large amount of water during the summer months.