Kochia

Kochia scoparia syn Bassia scoparia
Cultivated variety which maximises Autumn colour
Herb
Alternate
Simple
Yellow
Green
Red

Kochia is a bushy annual, growing to 1.5 m tall and wide in good conditions. It has an erect main stem with many upwards-curving side branches. The stems and leaves are generally green, but change to yellow, red and brown as the plant ages and dies. .

Kochia is a prohibited invasive plant under the Biosecurity Act 2014.

Common names 
Also known as: burning bush, summer cypress,
Family 
Amaranthaceae
Deciduous 
No
Flowering time 
Spring to summer
Native/Exotic 
Exotic
Origin 
Native to Europe and Asia
Notifiable 
Yes
State declaration 
Category 1
Council declaration 
As per State Declaration
Known distribution 

It has been introduced as an ornamental and become naturalised throughout most of Europe, Argentina, Canada, United States, Africa, New Zealand and parts of temperate Asia including China and Japan.

Kochia seed was deliberately planted in southwestern Western Australia in 1990 to supply forage and help rehabilitate salt-affected land. It was sown at 68 sites, covering a distance of almost 1000 km. By 1993 it had naturalised at 52 of these sites and spread to roadsides and pastures and other areas not affected by salt. Its weed potential becoming evident an eradication program successfully destroyed all plants in the region.

Habitat 

Kochia is able to grow in a wide range of soil types, and is drought tolerant. It thrives in warm, low rainfall environments such as the cereal-growing regions of the southern mainland states of Australia.

Habit 

Kochia is an erect annual shrub It has been grown as an ornamental hedge because of its dense conical shape and attractive colour in autumn.

 Because it is extremely efficient at using water, it thrives in warm, low rainfall environments such as the cereal-growing regions of the southern mainland states of Australia. It can contaminate crops and suppress the growth of nearby plants by releasing chemicals into the soil. Although palatable to stock, kochia may be toxic in large quantities. It can also alter fire regimes and reduce the abundance of native plants.

Stem and leaves 

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

Flowers and fruits 

The flowers are the same colour as the leaves. Flowers occur singly or in pairs, in hairy spikes 5–10 mm long, along the upper parts of the shoots where the leaf and stem join. The single seeds are dull brown, 1.5 mm wide and contained in a star-shaped fruit. .

Reproduction and dispersal 

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.