Phytopthora cinnamomi (PC) is a fungal disease that kills the roots of susceptible plants. The plants then die as they are no longer able to absorb nutrients and water from the soil. PC is commonly known as Root Rot, Cinnamon Fungus and Jarrah Die Back. It is estimated that in Victoria the disease could cause the death of more than 25% of the overstory plant species and 50-75% of understory plant species. In Western Australia it has caused widespread devastation to areas of natural bush and wildflowers.

Mobile spores of PC are attracted to the plants roots and are produced in great numbers under favourable conditions. The spores are carried in the soil water and any means of transmitting water or soil from one area to another will spread these spores. The fungus has a special resistant spore which allows it to survive in a resting state in the soil for long periods. Soil temperatures over 15ºc, wet and low porosity soil, and soil low in organic matter favour the spread of this disease.

Movement of any wet or dry soil, dust or water from an infected area can easily infect other areas. Movement of spores can take place on the tyres of vehicles, and to a lesser extent on the feet and bodies of animals, bushwalkers boots, tent pegs and other equipment.

Phytophthora is known to exist in many well known walking areas including the Grampians, Brisbane Ranges, Wilsons Prom and Kinglake. Not all infected areas are closed or signposted. For this reason when leaving an infected area it is vitally important that you remove all trace of soil or water from your boots and equipment by washing your tent floor and especially your boots, toilet trowel and tent pegs after the walk. Then wipe using a disinfectant with the active ingredient quaternary ammonium compound in solution at least 0.1% W/V. Most cheap no-name brand disinfectants will be suitable.

So how do we identify PC in the bush? This is not so easy as most of us do not carry a microscope around in our backpacks, but if you see an area of dead and dying plants most likely spreading out downhill and it is unlikely that it is caused by draught, salinity or water logging, PC could be present.

So it is good practice to wash mud from boots and equipment after every walk. Bear in mind that PC can also infect your garden. Start every day or extended walk with clean equipment and avoid known infected areas.

Parks Victoria have a brochure available for those interested.