Plant pathogen and weed management
This page contains information about how the city controls weeds and manages dieback, a plant disease common in jarrah and banksia trees.
The city’s Plant Pathogen Management Plan 2015 – 2019 outlines strategies to protect and preserve our natural surrounds from infection from diseases such as dieback, honey fungus, canker disease and sphaeropsis blight, all of which exist in the local area, and have no available treatment to eradicate.
Many plant pathogens occur naturally in soil and plants, and are an important part of functioning ecosystems. However, the above diseases cause the decline and death of susceptible plants, and have the potential to severely impact the city’s urban forest and the significant environmental, social and economic value of this asset.
The diseases are spread by movement of infected soil or plant matter, root-to-root contact, or by water or wind. Wounds from poor pruning techniques, and the impact of abiotic stress factors such drought, can increase a plants susceptibility to infection.
The plan outlines a long-term approach to building and maintaining healthy ecosystems to improve the resilience of susceptible plants to infection, as well as implementing equipment hygiene control measures, best practice urban forest management techniques, and increasing community awareness. The plan applies measures that will be applicable to any emerging plant pathogen within the city.
How you can help?
The diseases also affect native and ornamental plants in home gardens. They can be unknowingly introduced to the area through common gardening practices such as contaminated plants or greenwaste. You can help by:
- Using soil, gravel, potting mix and mulch by purchased from suppliers that have a high pasteurisation standard as demonstrated by compliance with the Australian Standard for Compost, Soil Conditioners and Mulches (AS 4454), or the ISO 9001 Quality Management System. The use of raw greenwaste from tree lopping companies is discouraged, as mulch that has not been composted and pasteurised increases the risk of new disease outbreaks
- Buying plants from nurseries accredited under the Nursery Industry Accreditation Scheme Australia (NIASA). Plants from road side stalls or stock sitting on nursery floors is at higher risk of carrying dieback.
The city has dieback treatment kits available for hire by local residents. For further information, please Parks and Environment Services on 9387 0942.
The City of Subiaco undertakes chemical weed control of road reserve areas throughout the city, including footpaths, traffic islands, kerbs, laneways and public open space throughout the year. The product used is Glyphosate Biactive, which is a non-volatile, water soluble liquid with non-selective herbicidal activity against weeds and grasses. Glyphosate Biactive is effectively neutralised on contact with the soil and does not provide residual weed control.
To advise the public that spraying is being undertaken, signs are displayed in accordance with health regulations. When applying herbicide to public open spaces, signs are displayed at the entrance to parks. When undertaking footpath, traffic island, kerb or laneway weed control, signs are displayed on vehicles involved with the operation.
The city notifies residents of upcoming weed control through advertisements in the Post Newspaper and Talk About Subi.
When does it occur?
Weed control is only undertaken in appropriate conditions. Weed control will not be undertaken when:
- wind conditions exceed 15 kilometres per hour
- it is raining (or rain is imminent)
- temperatures exceed 35 degrees
Laneway pruning and weed control usually occurs in July each year.
The city acknowledges that there is concern within the community in regard to the use of chemicals in public open space. The city complies with government regulation and ensures manufacturer recommendations are followed. It is the regulatory authorities' responsibility to ensure the regulations and products are appropriate for given situations.
Following recent news reports the Department of Health released the following:
"The International Agency for Research on Cancer (IARC) classifies glyphosate as a Group 2A, “probably carcinogenic to humans.” There is not sufficient evidence that glyphosate causes cancer in humans according to the full IARC monograph which was released on 29 July 2015. An international re-evaluation of glyphosate is also being undertaken by the Joint FAO/WHO Meeting on Pesticide Residues and the final report will be released in May 2016. The Australian Pesticides and Veterinary Medicines Authority are confident that the current robust risk assessment and the label instructions on all glyphosate products provide adequate protection for users, when this advice is followed. The Department of Health continues to monitor the re-evaluation of glyphosate and encourages Local Governments to utilise risk assessments as part of best practice for the safe application of all pesticides”.
Residents can opt to have their property placed on a weed control exemption list using the online form below. All property owners / occupiers who apply for exemption from the weed control program will be required to keep the areas adjacent their property weed free to the same standard that will be achieved by the chemical control method.
You can also register for exemption by contacting the city on 9237 9222.
Weeds growing over the kerb are controlled using herbicide. Where kerb lines are edged and maintained, these properties are not to be sprayed. Where weed growth exceeds 150 millimetres in height, the weeds are removed manually. Where cars are parked preventing close operation of the vehicle, hand application using the extent of the hose reel is required.
Weed control along footpaths is not to exceed 10 millimetres beyond the outside edges of the footpath. Where footpaths are edged and maintained, these properties are not to be sprayed. Where weed growth exceeds 150 millimetres in height, these are to be removed manually. Where cars are parked preventing close operation of the vehicle, hand application using the extent of the hose reel is required.
For further information on weed spraying, fill in an online enquiry form or call the city on (08) 9387 0942.