Weeds are any plant growing in the wrong place at the wrong time.
Plants can be introduced into new areas for use in gardens and in agriculture. An example of a plant introduced into Queensland through agricultural practices is prickly acacia. Prickly acacia was introduced to Queensland as a fodder tree. Free from it's natural control agents, this plant has flourished and has become a major pest of prime Queensland grazing land. Weeds are an environmental menace, smothering native vegetation and degrading native habitats upon which our native animals are dependent for food, shelter and nesting sites.