Pest Alert – Brown Patch on Fescue

— Written By
en Español / em Português

El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.

Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.


Inglês é o idioma de controle desta página. Na medida que haja algum conflito entre o texto original em Inglês e a tradução, o Inglês prevalece.

Ao clicar no link de tradução, um serviço gratuito de tradução será ativado para converter a página para o Português. Como em qualquer tradução pela internet, a conversão não é sensivel ao contexto e pode não ocorrer a tradução para o significado orginal. O serviço de Extensão da Carolina do Norte (NC State Extension) não garante a exatidão do texto traduzido. Por favor, observe que algumas funções ou serviços podem não funcionar como esperado após a tradução.


English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.

Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.

Collapse ▲

Brown Patch is a disease caused by the fungus Rhizoctonia solani. Rhizoctonia causes turfgrass disease in western North Carolina mid-July-August. This is the number one disease in home lawns.

brown patch fungus on fescue

Symptoms of the disease are water soaked, blackened and withered leaves that eventually turn light brown. These light brown patches are roughly circular and can coalesce into irregular patches. Sometimes during periods of high humidity such as early morning, a ring of blackish-purple, mycelium covered, wilting leaf blades called a ‘smoke ring’ encircles brown patches on cool season turfgrass such as fescue. The ptaches of brown leaves can surround green grass forming a ‘wagon wheel’ shape. Other symptoms include tan to straw colored leaf spots, and black sclerotia (resistant survival structures) on dead grass and thatch.

brown patch fungus on fescueEnvironmental conditions that favor disease development occur in the mid to late summer. Temperatures greater than 77°F are necessary for the fungus to germinate from sclerotia and grow. High humidity is another environmental factor that favors growth. Extended periods of leaf wetness for 10 hours per day for up to three consecutive days often initiates disease symptoms.

Cultural control of the fungus may be achieved by reducing leaf wetness. Less frequent watering, increased drainage and increased airflow may reduce disease incidence. Lower mowing heights seem to increase disease incidents, so raising the mower blades may decrease the chance brown patch will affect turf. Moderating fertility so that excess nitrogen is avoided is also crucial. The fungus is spread by machinery, so washing mowers after cutting diseased turf is critical in reducing disease spread.

brown patch SeptemberChemical controls for brown patch abound. Some chemicals that will control the disease are thiophanate methyl, chlorothalonil and mancozeb. There are many others as well. These fungicides should be sprayed over the entire turf stand to achieve control. Often a second treatment is necessary within the same season. It is also a good idea to treat the following summer to be on the safe side.

Management Tips:

  • Use low to moderate amounts of nitrogen, moderate amounts of phosphorous and moderate to high amounts of potash.
  • Avoid nitrogen applications when the disease is active.
  • Increase the height of cut.
  • Increase air circulation.
  • Minimize the amount of shade.
  • Irrigate turf early in the day.
  • Improve the drainage of the turf.
  • Reduce thatch.
  • Remove dew from the turf early in the day.