What is dieback?

Phytophthora (pronounced Fyt-of-thora) dieback is a devastating plant disease caused by a type of water mould, Phytophthora cinnamomi. It kills many susceptible plants such as banksias, jarrah and grass trees by attacking the root system and causing them to rot. Dieback is a symptom of Phytophthora infection.

It is believed that Phytophthora was introduced to Western Australia by plants bought in with first settlers.Phytophthora causes loss of biodiversity and extinction of threatened plant and animal species. Over 40% of native species in Western Australia are at risk.

How is dieback spread?

Phytophthora is spread through the movement of soil and water by vehicles including bikes, footwear and animals. Phytophthora dieback can easily be introduced to your garden from non-composted mulch, infected potting mix and nursery plants.

What can I do to prevent dieback?         

There is no known method to eradicate Phytophthora but we can minimise its spread and impact.


  • Look out for information signs around dieback infested areas and follow the instructions

  • Keep to designated footpaths and keep your pets on lead

  • Use ‘dieback hygiene stations’ where available to remove and sterilise soil from your boots and bikes

  • Ask nurseries if they use Phytophthora dieback control procedures and if they are accredited by the Nursery Industry Accreditation Scheme Australia (NIASA)


  • Travel in dieback infested areas during and after rain events when the soil is damp

  • Do not dump garden soil and plants into parks or bushland reserves

What does the City do to prevent dieback?

The City implements dieback hygiene procedures for staff and contractors who move in and out of bushland reserves. Equipment and vehicles are to be cleaned-down with a methylated spirits-solution before entering bushland reserves and when leaving Phytophthora infested areas.

The City runs an annual dieback management program where a suitably qualified contractor is engaged to map the presence of Phytophthora. Any reserves that are found to be infested are then treated with Potassium Phosphite to increase plant resilience.

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More information and Contact

Email [email protected]

Phone 08 9411 3444



City of Cockburn
Whadjuk Boodja
9 Coleville Crescent,
Spearwood 6163

PO Box 1215, Bibra Lake DC,
Western Australia, 6965

Office opening hours:
8.30am to 4.30pm
Monday to Friday (excluding public holidays)

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Cockburn Nyungar moort Beeliar boodja-k kaadadjiny. Koora, yeyi, benang baalap nidja boodja-k kaaradjiny.
Ngalak kaadatj dayin boodja, kep wer malayin. Ngalak kaadatj koora koora wer yeyi ngalang birdiya.

City of Cockburn acknowledges the Nyungar people of Beeliar boodja. Long ago, now and in the future they care for Country.
We acknowledge a continuing connection to land, waters and culture and pay our respects to the Elders, past and present.