Fescue lawns can occasionally develop a fungal disease known as brown patch. This disease thrives during periods of warm nights and high humidity and can cause unsightly patches or thinning turf.
Quick Brown Patch Tips
- Occurs during warm, humid weather
- Most common when nighttime temps exceed 65°F
- Morning watering helps reduce disease
- Lawns often recover when conditions improve
- Fungicides work best when applied early
What Is Brown Patch?
Brown patch is a fungal disease that affects cool-season grasses such as fescue. It commonly develops when nighttime temperatures remain above 65°F and humidity is high.
Symptoms include brown or thinning patches of turf. Grass blades around infected areas often show orange, tan, or brown spots or bands called lesions.
How to Identify Brown Patch
Brown patch is often mistaken for drought stress or insect damage. Taking a closer look at the turf can help determine the true cause.
Signs of Brown Patch
- Brown or thinning patches that appear during warm, humid weather
- Grass blades with tan, orange, or brown lesions or bands
- Damage often worsens during periods of high nighttime temperatures
How It Differs from Drought Stress
- Drought stress usually affects large areas evenly
- Grass may turn bluish-gray before browning
- Turf does not pull up easily and recovers quickly after watering
How It Differs from Grub Damage
- Grub-damaged turf pulls up easily, often like a loose carpet
- Roots are chewed or missing beneath affected areas
- Grub damage is most common in late summer
If grass blades show lesions and turf remains rooted firmly in the soil, brown patch is the likely cause.
How Serious Is Brown Patch?
In mild cases, lawns typically recover once weather conditions become less favorable for disease development. In more severe outbreaks, affected areas of turf may thin significantly or die.
Cultural Control Practices
The first step in managing brown patch is adjusting watering practices.
- Water lawns in the morning rather than the evening.
- Morning watering allows turf to dry during the day, reducing moisture overnight.
- Avoid excessive nitrogen fertilization during hot, humid weather.
Fungicide Control Options
When conditions favor disease development, fungicides can help prevent further spread.
- Apply products such as Ferti-lome F-Stop or Bonide Infuse.
- Treat preventatively when nighttime temperatures exceed 65°F and humidity is high.
- Follow label directions carefully for application rates and timing.
Please read and follow all label instructions when applying any lawn care products.