Noxious Weeds & Environmental Weeds

Noxious weeds

What are noxious weeds?

Weeds can be loosely defined as plants that are growing in the wrong place. Whether a plant is considered a weed depends on its behaviour in the environment. A plant may be regarded as a weed in one region of Victoria but not in another.

Many weeds can be easily controlled and do little more than cause a nuisance to a gardener or landholder. However some weeds are highly invasive and can cause economic loss or environmental damage. Termed 'noxious weeds', they can suppress desirable vegetation, harbour pests, provide a high fuel load for wildfires and reduce biodiversity in native plant reserves.

How can noxious weeds be controlled?

Noxious weeds are usually very hardy plants that are often difficult and sometimes very expensive to eradicate. Removing an infestation of noxious weeds can require several years of work. Most noxious weeds produce large quantities of seed and the seed can last for a long time in the soil. It is estimated that gorse, Ulex europaeus, seed can remain viable in the soil for up to 40 years. Gorse is a common noxious weed in the Ballarat region.

The State Government administers and enforces Noxious Weed Control Legislation through the Department of Sustainability and Environment - www.dse.vic.gov.au.
Plants are declared as weeds by the Victorian Catchment Management Authorities within their respective management regions across the state. The Ballarat municipal area crosses three catchment regional boundaries:

1. Corangamite Catchment Management Authority - www.ccma.vic.gov.au
2. Glenelg Hopkins Catchment Management Authority - www.glenelg-hopkins.vic.gov.au
3. North Central Catchment Management Authority. www.nccma.vic.gov.au

Weed lists and specialist weed control advice are available from the Department of Primary Industries website - www.dpi.vic.gov.au.

Noxious weeds are grouped into the following categories according to their potential to cause economic or environmental damage:

• State Prohibited Weed
• Regionally Prohibited Weed
• Regionally Controlled Weed
• Restricted Weed

The above categories determine who is responsible for the control of that weed.

State Prohibited Weeds for example are controlled by the State Government. They are weeds that are a serious risk to the environment, the States economy or possibly to public health. They are generally weeds that have not yet gained a significant foothold within the State.

Regionally Prohibited and Regionally Controlled Weeds are the responsibility of the landholder or land manager to control. Landholders and land managers need to be aware of which catchment management region their land is in and which weeds they are required to control on their own land and on any adjoining roadside verge. Noxious weed legislation does not differentiate between urban land and rural land.

As a land holder and land manager, the City of Ballarat is required to control Regionally Prohibited and Regionally Controlled Weeds on Council land. An annual Noxious Weed Control Program is undertaken to reduce the impact of weeds on our public open space.

As different weeds require different methods of control, the Citys weed control program uses a variety of methods including fire management, mechanical removal, herbicide control and biological control.

Environmental Weeds

What are environmental weeds?

Environmental weeds are plants that may not be declared weeds but do exhibit weedy behaviour - that is, they can invade and displace desirable plants in the environment. Environmental weeds are often common plants that have escaped from gardens and become established in the natural environment. Pampas grass, Cortaderia selloana, with its feathery seed heads is an example of a garden escapee that can invade local bushland.

In Victoria alone, more than 600 of our weed species have escaped from gardens. Illegal dumping of garden waste on vacant land and into bushland has allowed these weeds to invade natural areas. Blue periwinkle, English ivy and watsonia are common environmental weeds that can be found in the centre of Ballarat.

Some native Australian plants from other regions of the country can become environmental weeds when planted outside of their natural range. The Cootamundra Wattle, Acacia baileyana, is an example of an Australian plant that can invade bushland in this region.

How to avoid enviornmental weeds?

When planning a garden or purchasing plants visit a reputable nursery for advice on plant selection. Purchase varieties that are not potential environmental weeds.

Information on appropriate garden plant selection is also available on the Weeds Co-Operative Research Centre website at www.weeds.crc.org.au/bushlandfriendlygardens. Another excellent resource for information on plant species to avoid using in the garden environment is Environmental Weeds a Field Guide for SE Australia by Kate Blood.

Proper disposal of green waste and garden litter is essential to reduce future weed invasions in the Ballarat region. Green waste can be taken to either the Garden Recyling Centre in Learmonth Street, Alfredton, or to the City of Ballarat Waste Transfer Station in Gillies Street South where it will be processed and composted. Alternatively, you may organise to have your greenwaste collected by contacting Ballarat Organics on 03 5334 2621.

The City of Ballarat, the Department of Primary Industries, the Department of Sustainability and our neighbouring Councils have forged strong partnership links in the ongoing effort to control noxious and environmental weeds in the Ballarat region. The City of Ballarat is a member of the Weed Society of Victoria - www.wsvic.org.au.

See also - Biodiversity: ten things to do in your backyard (DSE website).