Quick Facts

Quick facts

  • Originally from Mediterranean region, Cape Broom (Genista monspessulana), a Weed of National Significance, is a yellow flowered shrub, 3–5 m tall, highly invasive with serious impacts on the environment, agriculture and the economy in southern Australia.
  • Readily invading pastures, native woodlands to grasslands, in temperate areas and out-competes other vegetation by shading and nitrogen fixation.
  • Spread by seed, mature healthy plants form dense impenetrable thickets that can produce many seeds per year forming a large long-lived seed-bank.
  • The movement of soil-stored seed by earth-moving machinery is a major way this weed is spread with early detection and good hygiene within infestations preventing spread.
  • Control is difficult, with effective control requiring a strategic program integrating a range of techniques including manual removal, burning and chemical applications, and biological control.
  • All control programs should aim to reduce the amount of seed produced, with prevention the most cost-effective form of weed control.
  • Tackle the small, outlying infestations before they set seed. This results in less follow-up where the seed-bank will be small.

What Does It Look Like?

What is it?

Cape Broom (Genista monspessulana) is an erect, evergreen, perennial shrub to 3 m high. The stems are ribbed and covered with short soft hairs. The leaves are shortly petiolate (on a short leaf stalk), also covered with short soft hairs. Leaves are trifoliate (divided into three leaflets) with the centre leaflet being slightly longer than the outer two. Leaflets are 5–25 mm long, 2–15 mm wide, sparsely hairy on the upper side, paler and more densely hairy on the lower side. Each leaflet is obovate (egg-shaped in outline with the widest part nearer the tip of the leaflet) with the base of the leaflet uniformly tapering to the leaf stalk. The top end (apex) of the leaflet is rounded with the tip ending in a small short point, with margins entire (not toothed or lobed).

The yellow pea flowers are 8-13 mm long and more or less clustered in groups of 3-7 at the ends of short branchlets in the axils of leaves. Flowering occurs from late winter to spring and early summer.

Mature fruits (seed pods) are dark brown to black, very hairy, 15-30 mm long and about 3-5 mm wide, each pod normally contains 5-8 seeds. Mature seed pods usually mature over late spring to early summer, when they open and expel seeds explosively and coil distinctively once opened (Office of Environment and Heritage 2014). The hard seeds are brown to black in colour, smooth and rounded and slightly flattened, about 2.5 mm across (Jeanes 1996; Weeds Australia).

Recognition: This species can normally be recognised by the combination of the following characters; young stems are ridged, green and lightly hairy; leaves on a short leaf stalk, are trifoliate (have three-leaflets), leaflets egg-shaped with widest point nearer tip, leaflet hairy – more so on their undersides each ends in a short point; flowers are bright yellow and pea-like, 8–12 mm long in clusters of 3 to 9; fruits (pods) are hairy all over, brown to black in colour when ripe, 15–25 mm long and 3–5 mm wide with 5–8 seeds; seeds are smooth, dark brown to black, up to 3 mm long.

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

Flower colour


Growth form (weed type/habit)


Where it currently grows? Preferred habitat

Cape Broom (Genista monspessulana) favours scrub and open woodland in its area of origin (Tutin et al. 1968). In Australia it occurs mainly in higher rainfall  of southern Australia, south-west corner of Western Australia and the south-eastern states, and readily invades disturbed areas such as native vegetation, roadsides, fencelines, creek margins and poorly managed pastures. It also colonises disturbed bushland vegetation especially grassland, woodland and open forest (Jeanes 1996; Parsons & Cuthbertson 1992; National Herbarium of Victoria 2007).

Montpellier broom can inhabit a broader range of habitats than Scotch broom because it tolerates warmer and drier Mediterranean climates 0t has also been found in wetlands 0n many areas of Australia Montpellier broom is found growing together with Scotch broom (Office of Environment and Heritage 2014).

Are there similar species?

Cape Broom (Genista monspessulana) is generally similar to other shrubs that have yellow pea flowers and leaves divided into three leaflets. These include some native plants could be mistaken for Broom species including;  Goodia species example; Goodia lotifolia, indigenous to the east coast of Australia (Muyt 2001); Bossiaea foliosa; Exocarpus species, for example Exocarpus strictus; Jacksonia scoparia; Pultenaea daphnoides (large-leaf bitter-pea); and Viminaria juncea (native broom or swiftbush).

Other weedy species that could be mistaken for Cape Broom including the introduced Genista and Cytisus species.

Cytisus scoparius (English brrom) is an erect shrub of a similar size, with larger yellow pea-like flowers, and smooth, (without hairs on the) stems and leaves. The young stems are deep green, five-sided or angled. Plants also have longer pods (fruits) to 70 mm long.

Genista linifolia (Flax-leaf Broom) is similar to Cape Broom but with a more sprawling habit and distinctively thin, lance-shaped leaflets that are dark green above and covered in silvery hairs underneath; the hairy seed pods are in clusters at branch tips are distinct. Plants can have a ‘silvery’ appearance from a distance.

Cape Broom may not always be readily distinguished from Genista stenopetala and Genista xspachiana. There are taxonomic difficulties in this group and hybridization between species occurs. These two species greater numbers of flowers in clusters than Cape Broom, and generally slightly larger leaflets. However, these features can grade into Cape Broom (Genista monspessulana).

Gorse (Ulex europaeus) is a very spiny shrub, of similar size, also with yellow pea-like flowers.

Why Is It A Weed?

What are its impacts?

Cape Broom (Genista monspessulana) is a Weed of National Significance (WoNS). It is regarded as one of the worst weeds in temperate Australia because of its invasiveness, potential for spread, and economic and environmental impacts. Approximately 600,000 ha or more of national, state and urban parks, and fallow land are already infested with Cape Broom (Sheppard & Henry 2012). Cape Broom grows quickly, produces large amounts of long-lived seed, and can tolerate diverse environmental conditions. Being a leguminous shrub, it fixes nitrogen and consequently increases soil fertility providing a favourable habitat for re-generation and germination of more Cape Broom and other introduced weeds. Cape Broom establishes a large long-lived seed-bank making it difficult to eradicate (Parsons & Cuthbertson 1992; Muyt 2001; Department of Primary Industries Victoria 2004).

Agriculture: Cape Broom forms dense thickets which exclude most other vegetation. Dense infestations in pastures reduce carrying capacity of grazing land, provide harbour for rabbits and foxes. Cape Broom is considered toxic to stock if grazed excessively, but in Australia no cases of poisoning have been reported. Forestry impacts – Cape Broom is a weeds of major concern to foresters as they grow quickly and out-compete native and plantation species (Office of Environment and Heritage 2014).

Native ecosystems:  Cape Broom forms dense thickets which exclude most other vegetation increasing fire fuel-loads, changing vegetation structure. It out-competes indigenous plants and discourages their regeneration by shading under-storey species and by using nitrogen fixation to increase soil fertility, increasing soil erosion by excluding grasses and ground-covers thereby increasing the amount of bare ground underneath (Office of Environment and Heritage 2014). Fires and soil disturbance in infested areas usually lead to mass germination of soil-stored seed. In some areas of remnant bushland Cape Broom is sufficiently established to be assumed to be an indigenous plant and is retained in the belief it is part of the natural environment.

Urban areas: Readily invades disturbed areas such as roadsides, fence-lines, and abandoned or uncared for land. The infestation of abandoned grazing paddocks on the peri-urban fringe by Cape Broom thickets is also a fire hazard that increases the risk of bushfires moving into residential suburbs.

How does it spread?

A medium-sized shrubof Cape Broom (Genista monspessulana) can produce over 8,000 seeds a year. The pods open explosively, projecting seeds up to 4 m.

The seeds are further dispersed naturally by ants, birds, animals and water.

Seed is also spread inadvertently by people in dumped garden refuse, in soil and mud on road graders, earth-moving equipment, shoes and vehicle tyres (Parsons & Cuthbertson 1992; Muyt 2001; Weeds of Blue Mountains Bushland). The movement of soil-stored seed by earth-moving machinery is a major way this weed is spread.

What is its history in Australia?

Cape Broom was originally spread within Australia as a hedge or garden plant in the first half of the 1800s and is still found in home gardens (Parsons and Cuthbertson 1992).

How To Manage It?

Best practice management

Control of Cape Broom (Genista monspessulana) is possible by chemical, mechanical, and biological means. However, when mature flowering plants are removed, many seedlings will germinate from the soil seed bank and  long term follow-up is critical. Integrated control methods (combining control techniques over time), with long term follow-up is advised for control success. Preventing spread in new areas is the best form of control and weed hygiene should always be employed. A long-term strategic program is required to effectively control Cape Broom concentrating on exhausting the large, long-lived seed-bank and preventing further additions to it. New infestations should be treated prior to plants reaching the flowering stage. Once plants start to produce seeds control becomes more difficult and dispersal to other areas is likely. Treated areas should be regularly checked for regeneration, particularly after fire and soil disturbance.

Chemical control: Larger plants can be cut and painted with a suitable herbicide. Smaller plants can be slashed to control their regeneration and any regrowth sprayed with a suitable herbicide. Various herbicide are effective and available for use, please see, Office of Environment and Heritage (2014)  and DPI NSW (2019) for further details. Herbicide application methods are:

Foliar spraying: For the application of herbicide solution to weed foliage in the form of a spray, a common method used for woody plants. Foliar spraying can be used to treat plants of all ages but can be less effective on older plants.

Cut-and-swab method (Cut stump treatment): is when each stem is cut off at ground level and immediately applying herbicide to the cut surface killing the plant to prevent regeneration from the rootstock.

Basal barking: This method involves applying herbicide mixed with an adjuant to the lower trunk or stem of woody plants up to around 50 mm in diameter to a height of 30-40 cm above ground level.

Stem injection (drill-and-fill): Stem injection delivers herbicide directly to the sapwood but is rarely used on brooms, but when used, it is for plants with stems over 50 mm in circumference.

Scrape-and-paint: This method involves scraping away a small section of the bark and applying herbicide directly onto the sapwood. It is an effective but rarely used technique normally used on larger plants.

Splatter or gas gun:  splatter guns were developed over thirty five years ago for sheep drenching and has been adapted for weed spraying using chemicals.

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

NOTE: Training is normally a requirement in most States and Territories for all or some of the methods.

Non-chemical control: Control methods are described in detail in Office of Environment and Heritage (2014).

Physical control:  Seedlings and smaller plants can be dug out with small tools, or pulled out by hand, preferably when the ground is moist and soft. This is normally used in new infestations that have not flowered or in area after mature plants have been removed, and this type follow-up removes the many new seedlings that would have subsequently germinated. Older senescent broom plants can be cut at or below ground level, sometimes without the subsequent use of herbicide as they usually do not re-sprout or coppice at that stage of their life cycle.

Mechanical control: Removal by clearing is a useful method of controlling large infestations of Cape Broom. Crushing, mechanical pulling plants, or slashing with machinery clears areas ready for follow-up control methods required when mass of germination of Cape Broom seedlings will occurs from the soil seed-bank.

Mulching: Mulching or grooming with a tractor or excavator-mounted mulcher cuts bushes off at ground level and processes them to fine mulch. The mulch provides some suppression of seedling growth leaving a cleaner site after control than some other mechanical methods.

Cultivation: Cultivation with disc or mouldboard ploughs is useful for breaking established roots and for follow-up treatment of seedlings and regrowth in large infestations.

Competition and management: Stock availability, adequate fencing and the establishment of strong pasture grasses are the keys to using grazing to improve broom management.

Fire:  Most adult plants are killed by fire, but some are capable of re-sprouting from the rootstock. Although the amount of soil-stored seed may be reduced by burning, effective control of Cape Broom can only be achieved by regular treatment of regenerating seedlings by hand-pulling or herbicide application for 3 to 5 years following fire (Muyt 2001; Department of Primary Industries Victoria 2004, Australian Weeds Committee 2011). Soil-stored seed is stimulated to germinate following fire and may continue to germinate for many years following burning.

Biological control: Cape Broom has 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. A number of biological agents have been identified (Department of Primary Industries Victoria 2004; Sheppard & Henry 2012). Two insects, the Cape Broom psyllid; Arytinnis hakani, and the weevil; Lepidapion nr argentatum, both give good control.

Does it have a biological control agent?

YES. One agent has been redistributed for Cape broom after an unauthorised introduction, the Cape broom psyllid (Arytinnis hakani) (Harvey et al 2023).

When does it grow? (lifecycle/growth calendar)

The seeds of Cape Broom (Genista monspessulana) germinate in both autumn and spring and plants produce their first flowers when about two years old. Flowering occurs mainly from August to November. Sometimes a second flowering occurs towards the end of summer. In the heat of spring and summer, seed pods ripen and burst, projecting seeds with considerable force. New growth is produced each winter and spring (Parsons & Cuthbertson 1992).

Where Is It Found?

Which states and territories is it found?


What areas within states and territories is it found?

Cape Broom (Genista monspessulana) is naturalised in Victoria, southern South Australia, widely in Tasmania, south-eastern and eastern New South Wales, the Australian Capital Territory, south-eastern Queensland and south-west corner of Western Australia (Jeanes 1996; Muyt 2001; Parsons & Cuthbertson 1992; National Herbarium of Victoria 2007).

Where does it originate?

Cape Broom is native to the Mediterranean region, Portugal and the Azores (Tutin et al. 1968).

National And State Weed Listings

Is it a Weed of National Significance (WONS)?


Where is it a declared weed?


Government weed strategies and lists – Weeds Australia

Is it on the National Alert List for Environmental Weeds?


Government weed strategies and lists – Weeds Australia

Is it on the Agricultural Sleeper List?


Government weed strategies and lists – Weeds Australia

Names And Taxonomy

Main scientific name

Genista monspessulana

Other scientific names (synonyms)?

  • Cytisus candicans (L.) Lam.
  • Cytisus monspessulanus L.
  • Genista candicans L.
  • Teline monspessulana (L.) K.Koch
  • Cytisus canariensis (L.) Kuntze (misapplied by Black, J.M. 1948, Flora of South Australia Edn 2. 2: 450.; Ewart, A.J. 1931, Flora of Victoria. 667.)
  • Genista maderensis (Webb & Berthel.) Lowe (misapplied by Eichler, Hj. 1965, Supplement to J.M.Black's Flora of South Australia (Second Edition, 1943-1957). 187.)

Does it have other known common name(s)?

Montpellier Broom, Broom, Canary Broom, Common Broom, French Broom, Soft Broom

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