They become declared weeds because of their negative impacts on primary industries, native vegetation and/or public health.
Declared weeds have restrictions on their movement, sale, notification and control. Landowners are responsible for managing them in South Australia.
Identifying weeds helps you find out the best ways to control them. To do this, download and use the free Weed Control app.
If you need more help you can:
If you have a bush block, and you’d like advice on how to manage your weeds, contact us to discuss this and we might be able to arrange a free property visit.
View the complete list of South Australia's declared plants on the Department of Primary Industries and Regions SA (PIRSA) website.
Caltrop’s woody burrs, with its sharp rigid spines, can cause injury in urban areas and recreational spots like ovals and parks, plus it’s a hazard in horticulture
Salvinia is regarded as one of the worst weeds in Australia as this free-floating aquatic, non-flowering fern grows quickly to form thick floating mats of vegetation
Water hyacinth is one of the world's worst invasive weeds as it forms dense vegetation mats on the surface of water which rapidly block and choke waterways
Fountain grass is an escaped garden plant and a highly invasive weed. It takes over bushland and threatens biodiversity.
Silverleaf nightshade is a significant weed of crops and pastures, in which dense infestations can reduce productivity by 20–40%.
Feral European olives are a major pest in native vegetation where they displace local species and degrade habitat for animals. They’re oil-rich, making them a significant bushfire hazard.
Blackberry is a sprawling shrub that has become widely established as a pest in native vegetation and pasture.
Gazanias are a low-growing perennial herb that has spread into our coastal dunes, onto agricultural properties and along roadsides.
African lovegrass is a summer growing, drought tolerant, hardy, perennial (lives on year to year) grass that invades pasture and native vegetation.
Bulbil watsonia is an aggressive bulb weed of native vegetation and invades idle pastures and roadsides.
Cape tulip (one-leaf (Moraea flaccida) and two-leaf (Moraea miniata)) is a highly invasive and toxic ‘bulb’ weed .
Chilean needlegrass is an unpalatable invasive grass, which invades native grassland, severely reduces pasture productivity and can injure stock.