Facts about Dieback*

•    The pathogen known as Phytophthora Dieback is a common and devastating plant disease in native plant communities in the south-west of WA.

•    Phytophthora means “plant destroyer”. The first unexplained death of jarrah trees was recorded in the early 1920s near Karragullen. It’s believed the disease was introduced to WA in cultivated plants brought in with the first settlers.

•    Once the pathogen infects the roots of a plant, it may begin to show symptoms of ‘dying back’.

•    Phytophthora Dieback is found in suburban gardens, landscaped areas, golf courses, plant nurseries with poor hygiene practices, horticultural plantations and bushland.

•    Phytophthora Dieback was thought to only affect the jarrah forest, but this is a common misconception, it is invading many native plant communities, including banksia woodlands, jarrah forest and coastal heathlands from Eneabba in the north to Cape Arid in the east. It also affects a range of plants including roses, azaleas, proteas, fruit trees and native plants.

•    Phytophthora Dieback spreads via the movement of spores through wet soil and from plant to plant through their root systems. Human activity in infested areas is the main method by which diseased soil is moved from place to place.

•    It can be spread by movement of infested gravel, road construction, animals and off-road vehicles. The risk of spread is greatest during spring and autumn.

•    Although there are effective treatments to slow the spread of Phytophthora Dieback, there is no known method to eradicate the pathogen.

•    There are a range of practices that can minimise the spread of Phytophthora Dieback or minimise the impact of the disease. These practices include: restricting access to uninfested areas, use of signage, cleaning vehicles and boots before entering healthy sites, scheduling activities for dry soil conditions, controlling drainage, use of dieback-free soil and plants and the use of Phosphite.

•    The spread of the disease can be minimised by asking for Dieback-free plants, gravel, potting mix, mulch and soil at your local nursery or garden centre.

•    Community members keen to get involved in protecting their local bushland areas should work with their local government authority, catchment group or community conservation group.


*Source – Dieback Working Group www.dwg.org.au