Complete Guide to Brown Patch Fungus

Brown Patch Fungus

As lawn care experts, Simply Green understands that unsightly Brown Patch Fungus can be irritating for Georgia homeowners. If this is a problem in your yard, or for someone you know who is struggling with this eyesore, the information presented here will help. In this overview, you will learn what Brown Patch Fungus is, what it looks like, what causes it, how it spreads and, most importantly, how to treat it. If Brown Patch Fungus has not afflicted your lawn yet, read below to learn how to protect it from this disease. 

What is Brown Patch Fungus?

Brown Patch Fungus is a common lawn disease caused by a fungal pathogen, Rhizoctonia solan. It begins to develop in warm, wet humid weather from late winter to late spring and spreads more rapidly during summertime. It can make a reappearance in late fall if the weather conditions are right. Brown Patch Fungus affects all types of grass, including rye, zoysia, fescue and bluegrass. Bermudagrass can be affected as well, but less damage will be done to this type of vegetation because it grows and spreads more rapidly. Brown Patch Fungus causes circular or irregular-shaped patches of brown, dead grass that can range from a few inches to several feet in diameter.

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What Does Brown Patch Fungus Look Like?

The most obvious symptom of Brown Patch Fungus is visible patches of dry, dead grass. In the early stages, these areas may be a few inches wide. They can quickly spread, however, to merge with neighboring spots to form larger, irregular-shaped patches. The edges of the affected grass may be a darker brown, and the blades may have a distinctive water-soaked appearance. In humid conditions, you may also notice a white or grayish “smoke ring” around the outer edge of the brown patch, which is a sure sign of Brown Patch Fungus.

What Causes Brown Patch Fungus?

Brown Patch Fungus thrives in warm, humid conditions from late April through October when grass can remain wet for long periods of time, temperatures are moderate and humidity is high–above 85%. Poor soil drainage, overwatering, low mowing heights, and compacted soil all contribute to the development of this disease. Additionally, excessive fertilization, particularly with nitrogen, and not enough phosphorus or potassium, can lead to an outbreak of Brown Patch Fungus.

How Brown Patch Fungus Spreads?

The two biggest culprits that lead to the spread of Brown Patch Fungus are infected grass clippings after mowing and walking from the infected grass onto your healthy grass. The fungus can also spread through contaminated lawn equipment, including mowers and weed trimmers. The fungus can remain in the soil for several years, so it is important to take preventative measures to avoid an outbreak.

How to Prevent Brown Patch Fungus?

Preventing Brown Patch Fungus starts with proper lawn care. Create an environment that does not invite its growth. Simply Green Lawn Care recommends following these simple steps to prevent the disease:

  1. Avoid over-watering: Water the lawn deeply and infrequently, rather than lightly and frequently. This will encourage deeper root growth and make the grass more resilient to disease. Watch the forecast, and avoid watering when rain is coming or humidity is high.
  2. Mow at the correct height: Mow the grass at the recommended height for your grass type. This will promote a healthier lawn and reduce stress on the grass. Clear the lawn of grass clippings after mowing.
  3. Improve soil drainage: If your soil is compacted, consider aerating the lawn to improve drainage. Additionally, avoid watering the lawn when the soil is already saturated by dew, rain or previous watering.
  4. Limit fertilizer: Over-fertilizing, can create an environment that is ideal for fungal growth. Limit the use of fertilizer to the recommended amounts for your grass type. Avoid high-nitrogen content and make sure phosphorus and potassium levels are adequate.  
  5. Practice good lawn care: Regularly remove debris and grass clippings from the lawn, and keep lawn care equipment clean to prevent the spread of Brown Patch Fungus.

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How to Treat Brown Patch Fungus?

If Brown Patch Fungus has already infected your lawn, there are steps you can take to treat the disease. Expect the healing process to take several weeks. The following treatments can help reduce the severity:

  1. Fungicide applications: A fungicide can be applied to the lawn to kill the fungus and prevent its spread. However, fungicides are most effective when applied early in the development of the disease.
  2. Adjust watering: Adjusting the watering schedule can help reduce moisture on the lawn and prevent the spread of the fungus.
  3. Increase air circulation: Increasing air circulation by pruning trees and shrubs can help reduce humidity on the lawn and prevent the spread of the fungus.
  4. Overseeding: Overseeding brings new seed and grass growth to a lawn that has reached maturity. Adding fresh seed can help fill in the bare patches left by the disease.

Simply Green’s Fertilization and Weed Control Service

Simply Green offers a variety of weed control and fertilization programs. Starting with a careful evaluation of your lawn, Simply Green experts will determine the best program for your property based on the type of grass, types of weeds, time of year and the underlying issues within your lawn. 

Simply Green specialists will service your yard every four to eight weeks, depending on the time of year, to ensure proper maintenance, superior weed control and effective fertilization. Simply Green Lawn Care Plus only uses high-quality products that are safe for your family and the environment.

Image contributor: NC State

About Simply Green Lawn Care

Picture of a Simply Green Spray Technician treating a lawn

Simply Green aims to provide the highest quality lawn care, mosquito control, and lawn pest control services to Georgia residents.


We are locally owned and operated which allows us to be accessible, attentive, and responsive for customers in Georgia.


Our well-trained team is easy to work with and determined to exceed expectations.


All our plant health care specialists are Georgia Department of Agriculture Certified and maintain their Category 24 applicators license.