Kochia (Bassia scoparia)

WEED ALERT: STATE PROHIBITED WEED
If you see this plant contact your council weeds officer, the NSW Invasive Plants & Animals Enquiry Line 1800 680 244 or email weeds@dpi.nsw.gov.au

Profile

Impact

Kochia is an erect annual shrub native to eastern Europe and western Asia. It has been grown as an ornamental hedge because of its dense conical shape and attractive colour in autumn, and has also been used as a fodder crop in salt-affected areas, but has since escaped cultivation and become a widespread and troublesome agricultural weed.

Kochia is resistant to insect attack, toxic to livestock and able to spread rapidly over long distances. It produces alleleopathic compounds that inhibit the growth of nearby plants.

In Australia it has the potential to infest pastures, crops, roadsides, railway lines and amenity areas. Once the plant gets into paddocks, it will significantly reduce pasture and crop production. 

The subspecies Bassia scoparia subspecies trichophylla (commonly known as summer cypress or burning bush) is not declared, and can still be found in older gardens. 

Distribution

Kochia is naturalised throughout Europe and parts of temperate Asia. It is recorded as a weed in Argentina, Canada and the United States.

Kochia was introduced to Western Australia in 1990 as a fodder plant for salt-affected land, but was since eradicated when its weedy potential in Australian conditions was recognised. It appeared in Tasmania as a contaminant of carrot seed in 1995, 1997 and 1998. All infestations have been eradicated and previously infested areas are checked annually.

Kochia is not known to be present in New South Wales (NSW).

Spread

Kochia reproduces by seed only. The species typically produces around 14 000 seeds per plant in late summer. Seeds are dispersed in autumn when the plant becomes a ‘tumbleweed’. Dead plants break off at ground level and are blown large distances by the wind. The tumbleweed habit is capable of spreading seeds up to a kilometre from where the plant was growing. Seeds appear to have a relatively short life in the soil, mostly germinating in spring or as suitable conditions allow.

Description

Kochia grows from 20–150 cm tall. It usually has a main stem that bears many upwardly-curving branches giving the plant a dense, conical appearance.

Key identification features

  • Leaves are flat and alternate, up to 5 cm long and 8 mm wide, with three longitudinal veins on the underside. Leaves are usually without petioles (leaf stems) and often have hairy margins. The young shoots are usually hairy.
  • Flowers are small and indistinct, located towards the tips of the branches.
  • Fruit are small (2 mm across), star-shaped and contain a single seed.

As the plant ages, its colour often changes from green to pale yellow, pink and then to rusty brown.

Habitat

Kochia is able to grow in a wide range of soil types, and is drought tolerant.

Acknowledgements

Written by Jeff Burton 2003; 2012 edition reviewed by Michael Michelmore.
Edited and prepared by Elissa van Oosterhout.

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Control

Contact your local council weeds officer for assistance with identification and control. Infestations can be spread by inappropriate control activities.

Herbicide options

Contact your local council weeds officer for control advice for Kochia (Bassia scoparia).

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Legal requirements

The content provided here is for information purposes only and is taken from the Noxious Weeds (Weed Control) Order 2014 published in the NSW Government Gazette, detailing weeds declared noxious in New South Wales, Australia, under the Noxious Weeds Act 1993. The Order lists the weed names, the control class and the control requirements for each species declared in a Local Control Authority area.

Except Bassia scoparia subspecies trichophylla

Area Class Legal requirements
All of NSW 1 State Prohibited Weed
The plant must be eradicated from the land and that land must be kept free of the plant

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Reviewed 2014