Quick Facts

Quick facts

• English Broom (Cytisus scoparius) is a native plant of western, southern and central Europe that is a large shrub with deep yellow flowers.
• It is naturalised in South Australia, New South Wales, Victoria and Tasmania.
• It is a highly invasive, environmental weed that has invaded over 200 000 hectares, and has continued to spread.
• It has invaded numerous native vegetation communities, and is one of the major weed threats in the alpine and subalpine areas of Australia.
• In agricultural situations it can form dense stands which reduce grazing and provide habitat for pest animals.
• Long term management programs based on an integrated weed management program will be the most efficient means of English Broom control.

What Does It Look Like?

What is it?

English Broom (Cytisus scoparius) is an erect, deciduous shrub to 4 metres high, with 5-angled branchlets. Leaflets are narrow-elliptic to oval with the broadest part in the upper half. The terminal leaflet is longer than the side leaflets, 4–20 mm long, 1.5–8 mm wide with the tip sharply pointed or round. Young leaves are often silky hairy on both surfaces, but sometimes hairless.

Flowers are usually 1 or 2 per junction between the stem and leaf stalk and deep-yellow. Occasionally they may be tinged with red or mauve or variously coloured in many cultivars, including white, cream, or with brownish-crimson lateral petals and a yellow upper petal.

The fruit is narrow, 25–60 mm long, 8–10 mm wide, flattened, silky hairy, turning black at maturity with 6–18 seeds released explosively when ripe (Webb et al. 1988; Jeanes 1996; Spencer 2002).

For further information and assistance with identification of English Broom contact the herbarium in your state or territory.

Flower colour

Yellow, White, Red

Growth form (weed type/habit)

Shrub

Where it currently grows? Preferred habitat

English Broom invades numerous native vegetation communities in southeastern Australia, generally favouring cooler and higher rainfall areas. It readily establishes in disturbed sites, such as on roadsides, and edges of bushland (Parsons & Cuthbertson 1992; Muyt 2001; National Herbarium of Victoria 2007).

Are there similar species?

English Broom is similar to White Spanish Broom (Cytisus multiflorus), but this species differs by having the branchlets rounded in cross-section and longitudinally ribbed, not more or less 5-angled in cross-section as in English Broom. English Broom usually has three leaflets over the whole plant, compared with three leaflets in the lower branches and a single leaflet in the upper branches for white Spanish Broom. The petals in white Spanish Broom are white, and 8-12 mm long, compared with the petals of English Broom which are 16-25 mm long, usually yellow, partly red or tinged mauve (Spencer 2002).

Other species with which English Broom can be confused include C. x dallimorei Rolfe, and C. x praecox Bean. C. x dallimorei is a hybrid between white Spanish Broom and English Broom (seed parent). The leaf stalks in English Broom are up to 15 mm long, the sepals are hairless, and the flowers are 15-25 mm long, whereas the leaf stalks in C. x dallimorei are up to 25 mm long, the sepals are slightly hairy, and the flowers are up to 15 mm long.. The flowers in C. x dallimorei are also pink, with crimson lateral petals. Cytisus x praecox is a hybrid between C. multiflorus and C. purgans. It differs from English Broom in usually having a single leaflet, and a style which is shorter than the lower 2 united petals (Spencer 2002).

Why Is It A Weed?

What are its impacts?

English Broom is a Weed of National Significance (WONS). It is regarded as one of the worst weeds in Australia because of its invasiveness, potential for spread, and economic and environmental impacts.

Agriculture: Although seedlings apparently do not readily establish in 'improved' pasture, in non-'improved' grazing areas, English Broom can prevent grazing, reduce the area available for grazing, and restrict access to water. Mature plants are relatively unpalatable to sheep and cattle, and in the United States the consumption of foliage by horses has resulted in digestive problems. The seeds are considered toxic to stock if eaten excessively (Parsons & Cuthbertson 1992; Hosking et al. 2000; Muyt 2001; DPIW 2002).

Native ecosystems: In Australia English Broom is mainly an environmental weed, and is highly invasive in the cooler, higher rainfall regions. The total area of infested in Australia is estimated currently as being over 200 000 hectares, and it is still spreading. It can have devastating impacts, and totally transforms invaded areas. It forms dense stands, which shade out the ground flora, and roadside infestations can also reduce drivers' vision and increase road maintenance costs. It commonly establishes in disturbed margins of native vegetation, from where it invades less disturbed native vegetation. Infestations also provide shelter for pest animals such as pigs and horses, which in turn pose a threat to native biota. It has invaded disturbed areas in national parks which have been cleared of blackberry infestations.

English Broom has invaded numerous native vegetation types in all the states where it is naturalised. In South Australia it is a common weed in the Southern Lofty Ranges. The species poses a very high risk to native vegetation, and has invaded heathlands and heathy woodlands, lowland grasslands and grassy woodlands, dry sclerophyll forest, wet sclerophyll forest, and alpine and subalpine areas (Carr et al. 1992). It is considered as one of the major invasive threats to the alpine and subalpine areas. It is abundant in the Mitta Mitta River valley, and around Falls Creek in Victoria. In New South Wales extensive areas of native vegetation have become infested. In the Barrington Tops north of Newcastle, an estimated 10 000 hectares has been invaded, and it is also a serious problem in the Blue Mountains. A number of orchid species and a daisy shrub that occur in the Barrington Tops are at risk from invasion (Parsons & Cuthbertson 1992; Sainty et al. 1998; Hosking et al. 2000; Muyt 2001).

How does it spread?

English Broom is spread solely by seeds, which are ejected explosively as the pods dry out on warm, sunny days during summer. Most of the seeds fall within a few metres of the parent plant. They are further dispersed by water (particularly if near streams), mud on machinery (such as road graders and slashers), vehicles and footwear. Birds, ants, cattle, horses and animal diggings are other means of dispersal (Parsons & Cuthbertson 1992; Muyt 2001).

What is its history in Australia?

The precise date of the introduction of English Broom to Australia is unclear. It is believed to have probably been introduced about 1800 after Governor King requested Broom seeds to be grown as a substitute for hops (Hosking et al. 2000).

How To Manage It?

Best practice management

In most situations, the most effective and long term control of English Broom will be an integrated weed management program (i.e. a combination of the above methods rather than by reliance on a single method) (Parsons & Cuthbertson 1992; Sainty et al. 1998; Cochrane 2001; Muyt 2001; DPIW 2002).

Chemical control: Herbicides are useful for both initial treatment and following other control methods (NSW Weedwise 2018). The most appropriate applications are either foliar spray or cut stump methods (NSW Weedwise 2018). When applying foliar sprays ensure that the mixture is applied to the point of run-off over the whole plant, and use a penetrant or surfactant as directed on the herbicide label (NSW Weedwise 2018). More than one application is usually necessary to be a successful control method.

Non-chemical control: Manual control: For isolated plants of English Broom hand weeding or hoeing is an option. In smaller incursions the cut and paint method can be applied. Bulldozing and then burning larger infestations of English Broom has been used, but this is best avoided unless there are resources for follow-up management. This is only a partial and temporary solution, as this method creates extensive soil disturbance which favours the germination of soil-stored seeds, which will continue to germinate for a number of years. There can be up to 20 000 seeds per square metre in the soil. The advantages are that the adult plants are killed, and the seeds are stimulated to germinate, thus quickening the process of waiting for seeds to germinate so they can be destroyed. Lack of follow-up management, such as spraying the seedlings with herbicide, only exacerbates the problem.

Grazing: Sheep, goats and cattle eat English Broom, particularly younger seedlings, and may suppress the development of infestations. Large plants can be cut to provide stock with better grazing access (SA Natural Resources 2015). 

Biological control: English Broom also been recognised as a target for biological control through a cross-jurisdictional government process. This allows activities to be undertaken to develop effective biological controls. An international biocontrol program involving Australia, New Zealand and the United States has been underway since 1990 to introduce a number of natural enemies to control English Broom. Two biological control agents, the Twig Mining Moth, Leucoptera spartifoliella (Hubner) and the Broom Cud Psyllid, Arytainilla spartiophila (Forster) were released in the north west, west and south of Tasmania in spring 1996 but follow up surveys have indicated these agents have failed to establish (DPIW 2002).

For more detailed information on control refer to Parsons & Cuthbertson (1992), Cochrane (2001), Muyt (2001) and DPIW (2002).

Please see the Australian Pesticides and Veterinary Medicines Authority for chemical information http://www.apvma.gov.au .

Does it have a biological control agent?

YES. Four biocontrol agents released against Scotch broom: Scotch broom twig mining moth (Leucoptera spartifoliella), Scotch broom psyllid (Artainilla spartiophila), Scotch broom seed bruchid (Bruchidius villosus), and Scotch broom gall mite (Aceria genistae) (Harvey,  et al 2023).

When does it grow? (lifecycle/growth calendar)

English Broom generally flowers between October and December. The peak plant growth period is during the spring-autumn period, but growth occurs throughout the year. The pods mature during summer, and the seeds are released on warm, sunny days. Autumn and spring rains initiate seed germination. Plants usually do not produce seed until at least three years of age. Individual plants are believed to live for 10-15 years (Parsons & Cuthbertson 1992; Muyt 2001).

Seed stored dry can remain viable for more than 80 years and more than 80% of buried seed can remain dormant and viable after 4 years (DPIW 2002).

Where Is It Found?

Which states and territories is it found?

NSW, SA, TAS, VIC

What areas within states and territories is it found?

English Broom is naturalised in South Australia, New South Wales, Victoria and Tasmania.

In South Australia it is common in the southern Mount Lofty Ranges as well as from Clare to Montrose.

In Victoria it is widely naturalised in the cooler, wetter parts of the state, mainly in the central highlands, particularly between Ballarat-Daylesford and Mt Macedon areas in the western part of the state. It is naturalised to the east of Melbourne such as the Dandenong Ranges, to the northeast of Melbourne and is becoming a problem in the alpine and subalpine areas. It is also naturalised near Corryong.

In New South Wales it is widely naturalised in the cooler, wetter areas regions of the state south from Glen Innes, including the Central Coast, Northern Tablelands, Central Tablelands, Southern Tablelands and Central West Slopes.

In Tasmania it also favours higher rainfall areas, and is most widespread in the northern part of the state (Parsons & Cuthbertson 1992; eFlora SA 2001; National Herbarium of Victoria 2007; PlantNET 2007).

Where does it originate?

English Broom is native to western, southern and central Europe, extending northwards to southern Sweden and eastwards to Ukraine (Tutin et al. 1968). It also occurs in the Macaronesia group of islands in the Atlantic (GRIN 2007).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?

YES

Where is it a declared weed?

ACT, NSW, SA, TAS, VIC, WA

Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?

NO

Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?

NO

Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Cytisus scoparius

Other scientific names (synonyms)?

• Cytisus scoparius f. sulphureus (Goldring) Rehder
• Cytisus scoparius var. andreanus (Puiss.) Dippel
• Cytisus scoparius var. prostratus (C.Bailey) F.Hanb. ex A.K.Jacks.
• Cytisus scoparius var. sulphureus Goldring
• Genista andreana Puiss.
• Sarothamnus scoparius (L.) Wimm. ex W.D.J.Koch
• Sarothamnus scoparius var. prostratus C.Bailey
• Spartium scoparium L.

Does it have other known common name(s)?

Broom, Scotch Broom, Common Broom, Scottish Broom, Spanish Broom