---
title: Brown Patch
canonical: https://gardensuperstore.com.au/problem-solver/brown-patch/
dateModified: 2026-08-07 09:45:00
summary: "Brown Patch is a fungal lawn disease that causes circular brown patches in warm, humid weather, especially on cool-season grasses."
type: article
keywords: [Brown Patch, Rhizoctonia solani]
---

# Brown Patch

> Brown Patch is a fungal lawn disease that causes circular brown patches in warm, humid weather, especially on cool-season grasses.

*Rhizoctonia solani*

Brown Patch is a fungal disease caused by the soil-borne pathogen *Rhizoctonia solani*. It affects a wide range of turf species but is particularly damaging on cool-season grasses such as tall fescue, ryegrass and bentgrass, though it can also appear on warm-season lawns under the right conditions.

The disease is most active during warm, humid weather, typically in late spring through to autumn, when night temperatures stay mild and leaves remain wet for extended periods. It spreads through prolonged leaf wetness, poor air circulation and excess nitrogen fertiliser, which encourages soft, lush leaf growth that is more susceptible to infection.

Management focuses on reducing the conditions that favour the fungus. This includes watering deeply but less frequently, watering early in the morning so leaves dry out during the day, improving airflow and light penetration by pruning back overhanging vegetation, avoiding heavy nitrogen applications during high-risk periods, and removing thatch build-up. Mowing equipment should be kept clean to avoid spreading the pathogen between areas.

## How to identify

- Circular or irregular brown or straw-coloured patches in the lawn, ranging from a few centimetres to over a metre wide
- A dark, greyish 'smoke ring' border around the patch edge, especially visible in early morning when the lawn is still damp
- Affected leaf blades show water-soaked, olive-green lesions that turn tan or brown
- Patches may appear sunken or thinned rather than completely dead
- Disease activity is worse after periods of high humidity, warm nights and heavy dew or overwatering

## Registered products we stock

- [Tombstone Duo | Fungicide](https://gardensuperstore.com.au/tombstone-duo-fungicide/) — ProForce
- [Mancozeb 750 DF | Fungicide](https://gardensuperstore.com.au/mancozeb-750-df-fungicide/) — David Grays
- [Chlortan 720 | Fungicide](https://gardensuperstore.com.au/chlortan-720-fungicide/) — PCT SureFire
- [Heritage Maxx | Turf Fungicide](https://gardensuperstore.com.au/heritage-maxx-turf-fungicide/) — Syngenta
- [Banrot 400WP | Fungicide](https://gardensuperstore.com.au/banrot-400wp-fungicide/) — ICL
- [Headway Maxx | Turf Fungicide](https://gardensuperstore.com.au/headway-maxx-turf-fungicide/) — Syngenta
- [Liquid Thiram | Fungicide](https://gardensuperstore.com.au/liquid-thiram-fungicide/) — Amgrow Specialty Agriculture
- [Mancozeb DG | Fungicide](https://gardensuperstore.com.au/mancozeb-dg-fungicide/) — Amgrow Specialty Agriculture
- [Quali-Pro Evolution Advance | Fungicide](https://gardensuperstore.com.au/quali-pro-evolution-advance-fungicide/) — Adama
- [Azoxystrobin 250SC | Fungicide](https://gardensuperstore.com.au/azoxystrobin-250sc-fungicide/) — EnviroMax
- [Banner Maxx | Turf Fungicide](https://gardensuperstore.com.au/banner-maxx-turf-fungicide/) — Syngenta
- [Banrot 80G | Fungicide](https://gardensuperstore.com.au/banrot-80g-fungicide/) — ICL
- [Chief Topflo | Systemic Fungicide](https://gardensuperstore.com.au/chief-topflo-systemic-fungicide/) — Adama
- [Clean Sweep Trio | Fungicide](https://gardensuperstore.com.au/clean-sweep-trio-fungicide/) — ProForce
- [Dacogreen 720 | Weathershield | Fungicide](https://gardensuperstore.com.au/dacogreen-720-weathershield-fungicide/) — Colin Campbell Chemicals
- [Dedicate FORTE Stressgard | Turf Fungicide](https://gardensuperstore.com.au/dedicate-forte-stressgard-turf-fungicide/) — Envu
- [Dedicate | Turf & Ornamental Fungicide](https://gardensuperstore.com.au/dedicate-turf-ornamental-fungicide/) — Envu
- [Exteris Stressgard | Turf Fungicide](https://gardensuperstore.com.au/exteris-stressgard-turf-fungicide/) — Envu
- [Flowable TMTD | Fungicide](https://gardensuperstore.com.au/flowable-tmtd-fungicide/) — Colin Campbell Chemicals
- [Instrata | Turf Fungicide](https://gardensuperstore.com.au/instrata-turf-fungicide/) — Syngenta
- [Interface Stressgard | Turf Fungicide](https://gardensuperstore.com.au/interface-stressgard-turf-fungicide/) — Envu
- [Lexicon Intrinsic | Fungicide](https://gardensuperstore.com.au/lexicon-intrinsic-fungicide/) — BASF
- [Liquid DEK | Fungicide](https://gardensuperstore.com.au/liquid-dek-fungicide/) — Colin Campbell Chemicals
- [Maxtima | Fungicide](https://gardensuperstore.com.au/maxtima-fungicide/) — BASF
- [Medallion | Turf Fungicide](https://gardensuperstore.com.au/medallion-turf-fungicide/) — Syngenta
- [Monstar SC | Fungicide](https://gardensuperstore.com.au/monstar-sc-fungicide/) — Colin Campbell Chemicals
- [Patriot | Fungicide](https://gardensuperstore.com.au/patriot-fungicide/) — Adama
- [Penncozeb 750DF | Fungicide](https://gardensuperstore.com.au/penncozeb-750df-fungicide/) — UPL
- [Quali-Pro Enclave | Fungicide](https://gardensuperstore.com.au/quali-pro-enclave-fungiciden/) — Adama
- [Rapide Aqua 500SC | Fungicide](https://gardensuperstore.com.au/rapide-aqua-500sc-fungicide/) — PCT SureFire
- [Reserve Stressgard | Turf Fungicide](https://gardensuperstore.com.au/reserve-stressgard-turf-fungicide/) — Envu
- [Sceptre 230SC | Fungicide](https://gardensuperstore.com.au/sceptre-230sc-fungicide/) — Colin Campbell Chemicals
- [Velista | Turf Fungicide](https://gardensuperstore.com.au/velista-turf-fungicide/) — Syngenta

## Image credits

- [Photo: Scot Nelson via Wikimedia Commons (CC0)](https://commons.wikimedia.org/wiki/File:Brown_Patch.jpg)