Serrated tussock is found in the south-eastern region of Australia. New South Wales, Victoria, the Australian Capital Territory, and Tasmania all have serrated tussock infestations.
Serrated tussock is a drought tolerant plant that is adapted to a wide range of climates and soil types.
Serrated tussock is native to the South American countries of Argentina, Uruguay, Chile and Peru. It was thought to be first introduced to Australia in the early 1900s, but was not officially recorded until 1935 at Yass, New South Wales where it has since expanded its distribution dramatically.
A patch of approximately 4 ha was first recorded in Victoria in 1954 in Broadmeadows (a suburb of Melbourne). This small patch had expanded to 30,000 ha by 1980 and then to 130,000 ha by 1998. Main infestations occur in the Melbourne, Geelong and Ballarat areas of Victoria.
Serrated tussock was first recorded in Tasmania in 1956 at Sandford near Hobart, although it had been known in the area since the late 1920s. By 1965 it was estimated that 3200 ha of land was infested. A state-funded eradication program undertaken in the 1970s and 1980s substantially reduced the infestation size. There is currently approximately 1700 ha still infested in Tasmania.
On a global scale, serrated tussock has naturalised and is considered weedy in New Zealand and South Africa. Small infestations also occur in England, France, Italy, Scotland and the United States.
In south-eastern Australia serrated tussock is now widespread and covers more than 2 million ha of land. It has occasionally been found, and eradicated, in South Australia. To date, it has not been found in Queensland, Western Australia or the Northern Territory.
Serrated tussock can grow on all types of terrain and will readily invade pastures, native grasslands and open scrub.
It will quickly infest bare ground and areas that have been disturbed, such as roadsides, overgrazed pastures or cultivated situations. It will colonise steep, rocky and timbered areas. These characteristics enable serrated tussock to quickly establish after times of drought.
Serrated tussock does not like to grow in heavily shaded areas, such as under a dense canopy of trees, or in damp or swampy ground. It is capable of withstanding a range of climates, but prefers cool temperate areas with an annual rainfall ranging 450−1000 mm. It does not tend to grow well in areas that experience hot summers (average over 30°C) and can tolerate freezing conditions.
Serrated tussock is not limited by soil type or fertility and will often be found growing in soil where there is little nutrition and/or low water. It grows on soils derived from slate, shale, limestone, ironstone, granite, basalt, sandstone, and mudstone (Campbell and Vere 1995).
Serrated tussock will readily grow in acidic soils but is rarely found in soils affected by salinity or water logging, preferring well drained areas to become established. While it will grow in very infertile soil, it also responds well to nitrogen or phosphorus fertiliser. Serrated tussock plants growing in fertile soil will often be larger in size than those growing in areas of low soil fertility.