what is a weed of invasive plant ?

‘An environmentally invasive plant’ is just another term for a weed. Quite simply, a weed is any plant that poses a threat to the environment, adversely impacts human or animal health, or causes crop or stock losses. For most gardeners, many of the characteristics we most desire in garden plants are the same as those that make them weedy: i.e. plants that are fast growing and disease resilient, and those which reproduce easily by the distribution of seeds or plant parts.

A modern definition of a weed is “a plant that requires some form of action to reduce its effect on the economy, the environment, human health and amenity”. A weed or invasive plant is a plant growing in the wrong place.

Invasive plants are defined and grouped as follows:

1. Noxious weeds - are those legally declared as noxious plants by the various state or territory governments. The declaration of noxious weeds will vary from state to state and from council area to local council area within a state or territory. In general, most state legislation will say that declared noxious plants cannot be grown, sold or transported or transposed, and removal is desirable.


2. Weeds of National Significance (‘WONS”) - are those plants which have been legally declared by the Federal government, with restrictions on their propagation, trade or sale applying to all States and territories.


3. Environmental weeds - Plants that are or have the potential to impact the natural environment by destroying habitat or overrunning indigenous species and altering local biodiversity. Many of our worst environmental weeds are garden escapes.


4. Agricultural & Horticultural weeds - are those plants that have a negative effect on crop or animal production. This may be through the infiltration of weed seed in grain crops, burrs in wool production or weeds which make animals sick or cause death. In the horticultural industry, weeds within cut flower crops can harbour pests and diseases which reduce productivity.