Why control woody weeds?

What is a problem weed?

A weed is any plant that is growing in an area that is shouldn’t be. However, there are a number of different classifications for a weed:

Noxious weeds – Serious problem weeds that are easily spread and are harmful to people or the environment. By law farmers need to control these weeds.

Weeds of National Significance – Introduced species that are highly invasive and have a big environmental and economic impact.

National Environmental Alert – Weeds that are introduced and are in the early stages establishing themselves that pose a threat to the environment.

Native plants considered weeds – These are weeds that while native to Australia, have extended beyond their natural range or habitat.

Why are weeds an issue for farmers?

Weeds aggressively compete with any other vegetation in the area. They invade crops, harm livestock and can quickly spread across a property and prevent any productive use of that land for farmers.

Weeds will compete with other native plants or pasture for the three things they need in order to grow:

• water
• sunlight
• nutrients in the soil.

In any patch of soil there is only a limited supply of these three things, meaning that if the weeds are growing, they are stealing those growth inputs that would otherwise be used by the native plants in that area.

Typically weeds will outgrow the native species or grasses in an area because they:

• Are not affected by the pests or diseases that would limit their growth in their natural habitat.
• Are better suited to the growing conditions of an area outside their natural habitat.

This means that weeds on a property will inhibit the growth of Australian agricultural products, whether that’s a livestock farmer that is struggling to maintain pasture to feed and grow his stock or a wheat grower who is having trouble growing the crop.

Why are weeds an issue for the environment?

The reason why weeds spread so quickly and grow so fast is because they have made their way into a habitat that is favourable to their growth, when usually there would be some environmental factors that would keep them under control.

When a weed enters an area it throws out the balance of that particular ecosystem, an ecosystem that has developed over many years and has achieved a balance allowing all the native species of plant in that patch of land to grow. Introduction of a new invasive species of plant that is more competitive and aggressive, means that the native vegetation that has slower growth or is more delicate, will be unable to continue growing and will die.

This effects not only the native vegetation but also any insect and animal species that relied on those plants for food.

For further information on how to control woody weeds visit:

• Herbicide application techniques
• Weed control timing