--- title: Brown Patch canonical: https://fernland.com.au/problem-solver/brown-patch/ dateModified: 2026-08-07 10:09:16 summary: "Brown Patch is a warm-weather turf disease caused by Rhizoctonia solani that produces circular brown patches, most damaging in humid conditions with extended leaf wetness." type: article keywords: [Brown Patch, Rhizoctonia solani] --- # Brown Patch > Brown Patch is a warm-weather turf disease caused by Rhizoctonia solani that produces circular brown patches, most damaging in humid conditions with extended leaf wetness. *Rhizoctonia solani* Rhizoctonia solani is a soil-borne fungus that survives between outbreaks as tough, dark brown to black resting structures called sclerotia, and as mycelium in thatch, soil and plant debris. During active infection the fungus produces coarse, brownish mycelium that can sometimes be seen as a fine, cobweb-like growth on leaf blades in the early morning while dew is still present, especially at the margin of an active patch. The fungus itself does not form conspicuous spores visible to the naked eye; diagnosis in the field relies more on patch pattern, the smoke-ring margin, and lesion appearance on individual leaves than on seeing the pathogen directly. Brown Patch affects most turf species grown in Australia, including couch, kikuyu, buffalo, ryegrass and fescue, and is one of the most common warm-season turf diseases in home lawns, sports fields and golf courses. It is driven by warm to hot temperatures, typically from spring through to early autumn, combined with prolonged leaf wetness from rain, heavy dew, overwatering or poor drainage. High humidity and still air, such as in shaded or poorly ventilated areas, favour disease development. Management relies on cultural practices that reduce leaf wetness duration and excess nitrogen, since lush, nitrogen-rich growth is more susceptible. This includes irrigating in the early morning rather than evening, improving surface and subsurface drainage, increasing airflow by pruning back overhanging vegetation, avoiding mowing when foliage is wet, and moderating nitrogen fertiliser inputs during high-risk periods. Removing excess thatch also reduces the environment the fungus favours for survival and spread. ## How to identify Affected turf shows roughly circular to irregular patches ranging from a few centimetres to over a metre across, initially water-soaked and dark, drying to a light brown or tan colour as the leaves die. A darker, smoke-grey to purplish ring can sometimes be seen at the active, expanding margin of the patch, particularly in early morning, and this ring fades as the day warms. Within a patch, the turf may appear thinned or sunken rather than completely dead, and unlike some other diseases, the crown and roots are often still alive, allowing regrowth once conditions improve. - **Damage signs:** circular brown or tan patches with a smoke-ring margin; leaf lesions with tan centres and darker brown borders; patches that expand slowly during warm, humid weather and can merge into larger irregular areas. - **Confirming the pathogen:** check for fine, greyish-brown mycelium on leaf blades early in the morning before dew dries; pull back affected turf and inspect for dark sclerotia in the thatch layer; the crown and roots typically remain firm and white rather than rotted. - **Lookalikes:** Fusarium patch/Microdochium produces smaller, pinkish-tinged patches and is more active in cool, wet conditions rather than warm weather. Dollar spot causes much smaller, silver-dollar sized patches with hourglass-shaped lesions on individual leaf blades. Drought or dog urine damage lacks the smoke-ring margin and does not spread with the same circular pattern over time. ## Registered products we stock - [Tombstone Duo Fungicide](https://fernland.com.au/tombstone-duo-fungicide/) — ProForce - [Banrot 400WP Fungicide](https://fernland.com.au/banrot-400wp-fungicide/) — ICL - [Sceptre Turf Fungicide](https://fernland.com.au/sceptre-turf-fungicide/) — Colin Campbell Chemicals - [Dacogreen Weathershield Contact Fungicide](https://fernland.com.au/dacogreen-weathershield-contact-fungicide/) — Colin Campbell Chemicals - [Mancozeb DG Fungicide](https://fernland.com.au/barmac-mancozeb-750/) — Amgrow Specialty Agriculture - [Penncozeb 750DF Fungicide](https://fernland.com.au/mancozeb-750df-fungicide/) — UPL - [Chlortan 720 Fungicide](https://fernland.com.au/chlortan-720-fungicide/) — PCT SureFire - [Instrata Triple-Action Turf Fungicide](https://fernland.com.au/instrata-triple-action-turf-fungicide/) — Syngenta - [Chief 625 Topflo Systemic Fungicide](https://fernland.com.au/chief-625-topflo-systemic-fungicide/) — Adama - [Clean Sweep Trio | Fungicide](https://fernland.com.au/clean-sweep-trio-fungicide/) — ProForce - [Heritage Maxx Turf Fungicide](https://fernland.com.au/heritage-maxx-turf-fungicide/) — Syngenta - [Azoxystrobin 250SC Fungicide](https://fernland.com.au/azoxystrobin-250sc-fungicide/) — EnviroMax - [Mancozeb 750 DF | Fungicide](https://fernland.com.au/mancozeb-750-df-fungicide/) — David Grays - [Velista Turf Fungicide](https://fernland.com.au/velista-turf-fungicide/) — Syngenta - [Liquid DEK Fungicide](https://fernland.com.au/liquid-dek-fungicide/) — Colin Campbell Chemicals - [Liquid Thiram Fungicide](https://fernland.com.au/liquid-thiram-fungicide/) — Amgrow Specialty Agriculture - [Medallion Turf Fungicide](https://fernland.com.au/medallion-turf-fungicide/) — Syngenta - [Quali-Pro Evolution Advance | Fungicide](https://fernland.com.au/quali-pro-evolution-advance-fungicide/) — Adama - [Flowable TMTD Fungicide](https://fernland.com.au/flowable-tmtd-fungicide/) — Colin Campbell Chemicals - [Headway Maxx Turf Fungicide](https://fernland.com.au/headway-maxx-turf-fungicide/) — Syngenta - [Patriot SC Fungicide](https://fernland.com.au/patriot-sc-fungicide/) — Adama - [Banner Maxx Turf Fungicide](https://fernland.com.au/banner-maxx-turf-fungicide/) — Syngenta - [Banrot 80G Fungicide](https://fernland.com.au/banrot-80g-fungicide/) — ICL - [Dedicate FORTE Stressgard Turf Fungicide](https://fernland.com.au/dedicate-forte-stressgard/) — Envu - [Dedicate Turf & Ornamental Fungicide](https://fernland.com.au/dedicate-turf-ornamental-fungicide/) — Envu - [Interface Stressgard | Turf Fungicide](https://fernland.com.au/interface-stressgard-turf-fungicide/) — Envu - [Lexicon Intrinsic | Fungicide](https://fernland.com.au/lexicon-intrinsic-fungicide/) — BASF - [Quali-Pro Enclave | Fungicide](https://fernland.com.au/quali-pro-enclave-fungicide/) — Adama - [Exteris Stressgard | Turf Fungicide](https://fernland.com.au/exteris-stressgard-turf-fungicide/) — Envu - [Maxtima | Fungicide](https://fernland.com.au/maxtima-fungicide/) — BASF - [Monstar SC Systemic Fungicide](https://fernland.com.au/monstar-sc-systemic-fungicide/) — Colin Campbell Chemicals - [Rapide Aqua 500SC Fungicide](https://fernland.com.au/rapide-aqua-500sc-fungicide/) — PCT SureFire - [Reserve Stressgard | Turf Fungicide](https://fernland.com.au/reserve-stressgard-turf-fungicide/) — Envu ## Image credits - [Photo: Scot Nelson via Wikimedia Commons (CC0)](https://commons.wikimedia.org/wiki/File:Brown_Patch.jpg)