Insects

• Insects can damage tall fescue grass. According to Lawn Care Academy, the grass "is subject to damage from a number of insects including white grubs, army worms, cut worms and leafhoppers." White grubs are the most damaging to fescue lawns. The best way to treat insect problems is with insecticides. If over-the-counter insect control does not halt the problem, commercial pest control companies will spray the lawn with a strong insect killer for a fee.
  
  

Environment

• The environment can help or hurt tall fescue grass. It grows best in organic and clay soils that are watered deeply. According to Aggie Horticulture, tall fescue grass becomes thin after a hot, dry summer, making it unsightly and creating clumps. If temperatures get too cold, the grass can suffer from winter damage. It does best in states that do not experience extreme heat or cold.
  
  

Diseases

• Brown patch is a common disease affecting tall fescue grasses. It is often seen in the presence of hot, humid weather, which is why it is best to plant tall fescue in geographical areas that do not experience extreme heat. According to Aggie Horticulture, other diseases affect the grass, such as fusarium blight. Fusarium blight can cause extensive damage to young fescue lawns, particularly those planted in the spring. Leaf spot is another disease that can cause problems for tall fescue. Once identified, treat the diseases with a fungicide or hire a professional to apply treatment to the lawn.