Arum lily (Zantedeschia aethiopica)
Arum lily (Zantedeschia aethiopica)

The role of DBCA’s Parks and Wildlife Service in managing weeds (invasive plants) is to:

  • Minimise the impacts of weeds on biodiversity, especially on threatened flora, fauna and ecological communities which are most vulnerable to their impacts.
  • Minimise the impact of weeds on cultural heritage sites, the amenity of public recreation areas and the aesthetic appeal of our natural environment for the appreciation and benefit of current and future generations. 
  • Minimise the impact of weeds on fire behaviour and fire regimes through hazard mitigation strategies and utilise opportunities to undertake post-fire weed control to facilitate regeneration of native species. 
  • Minimise the spread of priority weeds onto lands adjacent to Parks and Wildlife Service-managed lands.

 

What are weeds?

As defined by the department’s Weed Management Policy:

Weeds are plants (not necessarily non-native) that grow in sites where they are not wanted, and which have undesirable environmental or economic impacts, or both.

Weeds can reduce biodiversity, or adversely affect the integrity, conservation value and processes of ecosystems. They do this by, among other things:

  • successfully out-competing native species for resources including available nutrients, water, space and sunlight
  • replacing the native plants that animals use for shelter, food and nesting
  • impacting on native plants or animals due to toxins or excluding animals from usual habitats because of thorns or other adverse habit
  • providing habitat for introduced animal pests
  • altering fire regimes, potentially making fires more intense, and possibly altering their seasonality and frequency

Characteristics of invasive weeds

Both introduced and native plants have the potential to become weeds, if they have certain 'invasive' characteristics including:

  • Large volumes of seed
    The production of large volumes of viable seed which may remain dormant in the soil for many years
  • Effective dispersal mechanisms
    The use of spikes, hooks, wings or animal-attracting fruit to aid their dispersal
  • Rapid seedling growth and establishment
    The ability for seedlings to rapidly grow and establish in areas, out-competing other plants
  • Vegetative reproduction or regeneration
    The ability to regenerate or reproduce vegetatively
  • Disturbance invaders
    The ability to invade recently disturbed lands such as road verges and gravel pits
  • Allelopathy
    The ability to release self-protecting toxins that interfere with the growth of surrounding plants 

How to identify weeds

Weed identification procedures

  • Try and identify the plant yourself using available resources (see suggested resources below)
  • Ask an expert:
  • Use the MyPestGuide app to quickly identify pests and report your observations instantly to the Department of Primary Industries and Regional Development (DPIRD)
  • If you still can’t identify the plant, go to the WA Herbarium webpage for information on collecting and providing specimens to the Herbarium
  • If you think the weed you have found is a declared plant, contact the Pest and Disease Information Service or report it using the MyPestGuide Reporter app

Resources

There are many resources available to help you identify weeds and native plants.

Books and print

  • Western Weeds: A guide to the weeds of Western Australia’ Second Edition by B.M.J. Hussey et al. (2007) The Weeds Society of WA (Inc). (currently out of print)
  • ‘Weeds of the south-east: an identification guide for Australia’ Third Edition by F.J. Richardson et al. (2016) CSIRO Publishing. (Purchase this and other weed resources online: Weed Information.)
  • ‘Bushland Weeds: A practical guide to their management’ by K Brown and K. Brooks (2002). Environmental Weeds Action Network (Inc).
  • ‘Botanical Field Guide. New and Improved 5th Edition’ by S. Mager (2007). Aracaria Biodynamic Farm.

Software

Identification software available either online or as apps or CD.

Online

Florabase
Western Australian Herbarium online database for distribution of native and introduced (alien) plants across Western Australia

Atlas of Living Australia
An on-line resource containing information on all the known species in Australia aggregated from a wide range of data providers: museums, herbariums, community groups, government departments, individuals and universities

Australia’s Virtual Herbarium 
An on-line botanical information resource providing access to data in each of Australia’s nine herbaria

Australian Plant Name Index 
A tool that deals with plant names and their usage. Useful for translating a plant’s common name into its scientific name

Australian Plant Census 
A database of accepted scientific names for both native and introduced vascular flora of Australia

Weed Society of Western Australia 
Includes access to the Western Weeds online edition 1998 – please note that some information may be out of date

Weeds of Australia identification tool (Queensland Government)

Identification tool containing 1021 weeds

Weeds of Australia Fact Sheet Index (Queensland Government)

Website containing fact sheets for over 1000 weeds

Brisbane City Council Weed Identification Tool

A tool to assist in identifying weeds. Please note the information is intended as a guide only. Flowering and seeding times and foliage or flower colours may vary due to seasonal or local variability

iNaturalist and iNaturalist Australia

A global online community for naturalists which provides a species occurrence recording tool and a crowdsourced species identification system

What can you do to help stop weeds?

How are weeds spread?

Weeds are spread by:

  • wind and water
  • domestic, feral and native animals
  • through weed-infested products such as soil and manure
  • pot plants from markets and fetes
  • purchasing seed from mail order catalogues
  • inappropriate disposal of unwanted plant material, including the disposal of unwanted aquarium plants in drains/waterways and garden waste in bushland
  • people directly on their clothing, camping equipment, vehicles and machinery.

How can you help?

Weed management requires coordination among all levels of government in partnership with industry, land and water managers and the community, regardless of tenure.

  • Check all clothing, animals, vehicles, boats, trailers, caravans, camping gear and other equipment for weeds
    • remove all plant material and seeds and wash or brush down equipment
    • pay special attention to the undercarriage and tyres of vehicles
  • Bag and dispose of garden waste responsibly
  • Ask your nursery for soil and landscaping materials that are free of weed seed
  • Choose nursery plants that are local native species or plants of low weed risk
  • Use the Nursery and Garden Industry Australia (NGIA) Grow Me Instead resources or refer to the Water Corporation's Waterwise Plant Search

For more detailed information on how you can help refer to the Weeds in Australia website.

How to control weeds

Weed control methods

There are many methods available to manage the impact of weeds:

Chemical weed control

The following are requirements when planning a chemical weed control program.

  1. All chemicals must be used in accordance with the label specifications and be accompanied by the appropriate Material Safety Data Sheet (MSDS).
  2. Seek advice from your local chemical supplier.
  3. If you wish to use a chemical at a different rate to that recommended on the label or apply chemicals to species not listed on the label, refer to one of the minor use permits below (see Minor Use Permits).
  4. If the species is not listed on Minor Use Permit # 13333, # 13236 or # 82305, contact the Australian Pesticides and Veterinary Medicines Authority for more information.
  5. Consider how you will manage spray drift and non-target damage.
  6. Consider Occupational Health and Safety factors, particularly in relation to appropriate training and Personal Protective Equipment (PPE).
  7. Consider your legal requirements in relation to chemical use, pollution and native vegetation. When undertaking weed control in bushland areas that contain Threatened Flora and Threatened Ecological Communities, you must apply for a permit. 
  8. If conducting control near waterways, refer to the   Herbicides: guidelines for use in and around water(270KB PDF).
  9. For more information, refer to  Herbicides: knowing when and how to use them(197KB PDF).

Minor use permits

Minor Use Permit # 13333 - This permit allows persons to use products in the manner specified in the permit in designated jurisdictions and for specific species.

Minor Use Permit # 13236 – This permit allows persons to use products in the manner specified in the permit in designated jurisdictions for the control of declared plants in Western Australia.

Minor Use Permit # 82305 - This permit allows persons to use products in the manner specified in the permit in designated jurisdictions for the control of mesquite in rangelands in Western Australia.

Note – always ensure you check the expiry date of the permit.

Weed control resources

How does Parks and Wildlife Service manage weeds?

Prioritisation process for weed management

Parks and Wildlife Service’s species-led prioritisation process assesses weeds in each region based on:

  • ecological impact
  • invasiveness
  • current distribution
  • potential distribution
  • feasibility of control

The resulting priorities focus on weeds considered to be high impact, rapidly invasive and still at a population size that can feasibly be eradicated or contained to a manageable size.

This means that weed species which are already widespread are not ranked as a high priority through this species-led process.

The next stage of the process identifies high value biodiversity assets, the weeds that pose a threat to these assets, and the sites where control will have the greatest benefit and cost effectiveness. Social, cultural and economic assets as well as good neighbour issues are considered at a later stage of the process.

See Weed Prioritisation Process(135KB PDF) for further details on the context and methodology of the process, including how each weed was scored.

Summaries of the species ecological impact and invasiveness rankings are provided here to help other landholders, community groups and private enterprises manage weeds that might impact on the natural environment.

Ranking summary results by Parks and Wildlife Service region

Species-led ecological impact and invasiveness ranking summary results by region. The following Excel documents can be sorted by columns to find the information you require.

Notes on using the ranking summaries

Some species that are native to specific regions of Western Australia occur on these prioritisation lists as they have shown 'weedy' tendencies outside their natural range, such as on islands in the Pilbara region. 

The prioritisation for individual weeds within a Parks and Wildlife Service region should be treated as a guide and does not diminish any other requirements of land managers or developers, such as declared plants requirements of the Biosecurity and Agriculture Management Act 2007 or Ministerial requirements under Part IV of the Environmental Protection Act 1986.

Further weed management resources

Parks and Wildlife Service policies and legislation including the Weed Management Policy and Good Neighbour Policy can be found on the policies and legislation page.

For information on weeds in specific marine and terrestrial parks and reserves refer to the Parks and Wildlife Service management plans.

Other important strategies and documents

Useful links

WA Regional NRM groups

Grants information

Weed alert species

Phytolacca Americana) - Pokeweed fact sheet (1MB PDF)


Looking for information? contact us at weeds@dbca.wa.gov.au.

Page reviewed 10 Aug 2021