A healthy, green lawn is the pride of many North Texas homeowners, but even the best-kept yards can fall victim to lawn diseases.
These fungal and environmental issues can spread quickly, leaving brown patches, thinning turf, or strange discolorations across your yard. The sooner you can spot the warning signs, the faster you can treat them and restore your lawn’s health.
Below, we’ll walk through the most common types of lawn disease, how to identify them, and what you can do to prevent them in the future.
1: Brown Patch
What it Looks Like
Circular patches of light brown or yellow grass, often several inches to several feet wide.
Sometimes rings form, creating a “smoke ring” appearance with healthy grass in the middle.
Most noticeable in the morning when grass is damp with dew.
Why it Happens
Brown Patch is caused by the fungus Rhizoctonia solani. It thrives in hot, humid weather, which North Texas summers and early falls provide in abundance. Overwatering or watering in the evening can make conditions worse.
Grass Types Affected
Common in St. Augustine and Zoysia lawns, but can appear in Bermuda as well.
How to Manage it
Water deeply but less frequently, always in the early morning.
Improve air circulation by keeping grass at the right height.
Apply a fungicide if the disease spreads.
2: Dollar Spot
What it Looks Like
Small, silver-dollar-sized spots of bleached or straw-colored grass.
Spots often merge into larger irregular patches.
Fine cobweb-like fungal threads may be visible in the morning dew.
Why it Happens
Caused by Sclerotinia homoeocarpa, Dollar Spot thrives in warm days and cool nights, especially in lawns that are under-fertilized.
Grass Types Affected
Common in Bermuda and Zoysia lawns.
How to Manage it
Fertilize regularly with nitrogen, since nutrient deficiencies make lawns more vulnerable.
Water deeply but avoid frequent shallow watering.
Apply fungicides if Dollar Spot persists.
3: Gray Leaf Spot
What it Looks Like
Small brown spots with gray, fuzzy centers on grass blades.
Blades may curl, wither, and die.
Often confused with drought stress or heat damage.
Why it Happens
This fungal disease (Pyricularia grisea) thrives in hot, humid summers and spreads quickly with excess nitrogen and moisture.
Grass Types Affected
A major problem in St. Augustine grass.
How to Manage it
Water in the morning to reduce prolonged leaf wetness.
Avoid over-fertilizing with nitrogen during hot months.
Use fungicides when necessary.
4: Rust
What it Looks Like
Grass blades look dusty or coated in orange, red, or yellow powder.
Rust rubs off easily on shoes, pets, or mower blades.
Lawns look thin, weak, and discolored overall.
Why it Happens
Rust is a fungal disease that develops in shady, damp areas with poor circulation. Lawns weakened by drought or low fertility are more susceptible.
Grass Types Affected
Found in Bermuda, Zoysia, and Fescue lawns.
How to Manage it
Fertilize with nitrogen to encourage strong growth.
Improve air flow by pruning nearby trees or shrubs.
Mow regularly and collect clippings to reduce spore spread.
5: Fairy Ring
What it Looks Like
Dark green rings or arcs of grass, sometimes accompanied by mushrooms.
Rings can range from a few feet to several yards in diameter.
Grass inside the ring may turn brown or die off.
Why it Happens
Fairy Rings are caused by several soil-borne fungi that break down organic matter, releasing nitrogen that creates the dark green rings.
Grass Types Affected
Can appear in all grass types in North Texas.
How to Manage it
Aerate the soil to improve water penetration.
Water deeply to break up fungal growth in the soil.
Fungicides are sometimes effective but may require multiple treatments.
6: Take-All Root Rot
What it Looks Like
Yellowing patches that eventually thin out and die.
Roots appear black and rotted when pulled up.
Lawn feels spongy underfoot.
Why it Happens
Caused by Gaeumannomyces graminis, this disease attacks grass roots, especially in compacted or poorly drained soils. It’s particularly aggressive during wet, mild winters and springs in North Texas.
Grass Types Affected
Primarily affects St. Augustine grass.
How to Manage it
Improve drainage and reduce soil compaction.
Apply soil amendments like peat moss to reduce alkalinity (common in North Texas clay soils).
Fungicide treatments may be needed for severe outbreaks.
7: Powdery Mildew
What it Looks Like
White, powdery growth on grass blades.
Grass may look grayish or faded overall.
Lawn thins out in shaded areas.
Why it Happens
Powdery mildew thrives in shady, damp conditions with poor airflow. Lawns with excessive thatch are more vulnerable.
Grass Types Affected
More common in fescue and Kentucky bluegrass, but can appear in shaded areas of Bermuda or Zoysia.
How to Manage it
Improve sunlight exposure by trimming trees.
Reduce watering in shaded areas.
Apply fungicides in persistent cases.
8: Pythium Blight
What it Looks Like
Greasy, water-soaked patches that rapidly turn brown.
Cottony, white fungus visible in the early morning.
Spreads quickly in streaks, often following mowing patterns.
Why it Happens
This aggressive fungal disease (Pythium aphanidermatum) thrives in hot, humid, and wet conditions. Overwatering or poorly drained soils create the perfect environment.
Grass Types Affected
Affects Bermuda and Zoysia, especially on young or newly seeded lawns.
How to Manage it
Improve drainage and reduce excessive watering.
Avoid mowing when grass is wet.
Apply fungicides promptly to prevent rapid spread.
9: Summer Patch
What it Looks Like
Irregular patches of wilted or brown grass, often ring-shaped.
Turf thins and dies from the roots upward.
May look like drought stress at first glance.
Why it Happens
Caused by Magnaporthe poae, Summer Patch thrives in hot weather and compacted soils.
Grass Types Affected
Most common in Bermuda and Zoysia lawns.
How to Manage it
Aerate soil to relieve compaction.
Maintain proper mowing height and watering schedule.
Apply fungicides as needed.
10: How to Tell Lawn Disease From Other Problems
Not every brown or thinning patch means disease. Other common culprits in North Texas include:
Drought Stress (bluish-gray grass, especially near sidewalks and driveways).
Chinch Bug Damage (spreading patches in sunny areas of St. Augustine).
Dog Spots (circular patches from pet urine).
Nutrient Deficiencies (overall yellowing instead of distinct patches).
When in doubt, consult a lawn care professional who can correctly identify the problem and recommend treatment.
11: Preventing Lawn Disease
The best defense is a healthy lawn. Here’s how North Texas homeowners can reduce the risk of disease:
Water deeply and in the morning.
Aerate compacted soils annually.
Fertilize with the right nutrients for your grass type.
Keep mower blades sharp.
Control thatch buildup.
Monitor regularly for early signs of trouble.
12: Protecting Your North Texas Lawn
Lawn diseases can be frustrating, but with the right knowledge, you can spot the signs early and take action before they spread. Whether it’s Brown Patch in your St. Augustine or Dollar Spot in your Bermuda, identifying the issue quickly makes recovery much easier.
Ready to strengthen your lawn against disease? Schedule a core or liquid aeration service or get a quote for lawn services today with Gecko Green. Aeration improves soil health, root growth, and resilience, making your lawn less vulnerable to disease year-round.
