--- title: Botrytis canonical: https://gardensuperstore.com.au/problem-solver/botrytis/ dateModified: 2026-08-07 09:38:30 summary: "Botrytis (grey mould) is a common fungal disease that causes fuzzy grey spore growth and rot on flowers, leaves and fruit in cool, damp conditions." type: article keywords: [Botrytis, Botrytis spp.] --- # Botrytis > Botrytis (grey mould) is a common fungal disease that causes fuzzy grey spore growth and rot on flowers, leaves and fruit in cool, damp conditions. *Botrytis spp.* Botrytis, commonly called grey mould, is caused by fungi in the genus Botrytis, with Botrytis cinerea being the most widespread species in Australian gardens. It is one of the most common fungal problems affecting ornamentals, vegetables, berries and stored produce, and it can attack almost any soft plant tissue including petals, leaves, stems and fruit. On infected tissue you'll first notice soft, water-soaked brown patches. As the disease progresses, a fuzzy, greyish-brown fungal growth develops over the affected area, made up of masses of fine spores. This furry grey coating is the fungus's spore-producing structure and is the clearest sign of Botrytis, releasing spores that spread easily on air currents, splashing water and by touch. Small black, hard resting bodies called sclerotia can also form in severely rotted tissue, allowing the fungus to survive in plant debris or soil over unfavourable periods. Botrytis thrives in cool, humid, still conditions, particularly during Australian autumn, winter and early spring in temperate regions, or after extended wet or overcast weather anywhere in the country. It spreads readily where air circulation is poor, foliage stays wet for long periods, or plants are overcrowded. Damaged, ageing, or senescing plant tissue (such as spent flowers) is especially vulnerable, giving the fungus an easy entry point before it moves into healthy growth. Management relies on cultural practices: improving airflow through pruning and adequate plant spacing, avoiding overhead watering (especially late in the day), promptly removing spent flowers, dead leaves and rotting fruit, and clearing plant debris from the garden. Reducing humidity around susceptible plants, such as by opening up greenhouses or glasshouses, also helps limit outbreaks. ## How to identify - Soft, brown, water-soaked lesions on petals, leaves, stems or fruit that expand over time - A fuzzy, greyish-brown fungal growth (spore mass) developing over affected tissue, especially in damp weather - Flower buds or blossoms that fail to open properly, turn brown and rot (blossom blight) - Soft rot in stored fruit or bulbs, often starting at a wound or bruise - Small black, hard resting bodies (sclerotia) sometimes visible in badly rotted tissue - Affected tissue collapses and becomes slimy or dry and papery as it dies**Field check:** gently tap or disturb a suspect grey, fuzzy patch — Botrytis spores will often puff off visibly, and the fungal coating feels soft and powdery rather than slimy or sticky. Botrytis is sometimes confused with *powdery mildew*, but powdery mildew forms a dry, white-to-grey dusty coating on the upper leaf surface without the soft brown rot underneath, whereas Botrytis is associated with tissue decay and a fuzzier grey-brown growth. It can also be mistaken for general bacterial soft rot, which produces a slimy, foul-smelling breakdown of tissue without the characteristic fuzzy grey spore coating. ## Registered products we stock - [Tombstone Duo | Fungicide](https://gardensuperstore.com.au/tombstone-duo-fungicide/) — ProForce - [Chlortan 720 | Fungicide](https://gardensuperstore.com.au/chlortan-720-fungicide/) — PCT SureFire - [Copper Oxychloride | Fungicide](https://gardensuperstore.com.au/copper-oxychloride-fungicide/) — Amgrow Specialty Agriculture - [Serifel | BioFungicide](https://gardensuperstore.com.au/serifel-biofungicide/) — BASF - [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 - [Stellar | Fungicide](https://gardensuperstore.com.au/stellar-fungicide/) — PCT SureFire - [Switch | Fungicide](https://gardensuperstore.com.au/switch-fungicide/) — Syngenta - [Cheers 720 | Weathershield | Fungicide](https://gardensuperstore.com.au/cheers-720-weathershield-fungicide/) — Colin Campbell Chemicals - [Chief Topflo | Systemic Fungicide](https://gardensuperstore.com.au/chief-topflo-systemic-fungicide/) — Adama - [Dedicate | Turf & Ornamental Fungicide](https://gardensuperstore.com.au/dedicate-turf-ornamental-fungicide/) — Envu - [Penncozeb 750DF | Fungicide](https://gardensuperstore.com.au/penncozeb-750df-fungicide/) — UPL - [Rapide Aqua 500SC | Fungicide](https://gardensuperstore.com.au/rapide-aqua-500sc-fungicide/) — PCT SureFire ## Image credits - [Photo: Rasbak via Wikimedia Commons (CC BY-SA 3.0)](https://commons.wikimedia.org/wiki/File:Aardbei_Lambada_vruchtrot_Botrytis_cinerea.jpg) - [Photo: Dr. Jutta Gabler, Institute for Epidemiology and Pathogen Diagnostics of the Julius Kühn Institute (JKI), Federal Research Centre of Cultivated Plants, D-06484 Quedlinburg, Germany via Wikimedia Commons (CC BY-SA 4.0)](https://commons.wikimedia.org/wiki/File:Basilikum_Botrytis_cinerea_Befall--J-Gabler.jpg) - [Photo: Flowersabc via Wikimedia Commons (CC BY-SA 2.0)](https://commons.wikimedia.org/wiki/File:Botrytis_cinerea_-_5775778185.jpg) - [Photo: Schlaghecken Josef via Wikimedia Commons (CC BY 4.0)](https://commons.wikimedia.org/wiki/File:Blumenkohl-Winter-Botrytis-QBH-2006-03-27-Josef_Schlaghecken.jpg)