Cape Broom / Montpellier Broom

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Cape Broom / Montpellier Broom	LC0185
Department of Primary Industries Updated: September 2007 To view the Adobe Acrobat file, you will need the Adobe Acrobat Reader (external link).	(PDF 424kb)

Common and Scientific Names

Cape broom, Montpellier broom
Genista monspessullana (L.) L.A.S. Johnson

Origin and Distribution

Cape broom is native to scrub and open woodlands in the Mediterranean region, Portugal and the Azores. It was probably introduced to Australia as a garden or hedge plant and was widely planted last century. In Victoria, cape broom infestations occur mainly on grazing lands and dry sclerophyll forests and woodlands of southern, central and north-eastern regions.

Description

Cape broom is an upright evergreen shrub up to 3m high, but more commonly 1 to 2 m, which reproduces by seed. Young plants are capable of flowering and fruiting at approximately 2 years old.

Stems - Erect, ridged (but not five-sided), woody; usually one main stem with many branches.

Leaves - Consist of 3 leaflets attached centrally to a short stalk, with the central leaflet slightly longer than the rest, up to 40 mm long. Leaflets have less hair on the upper surface than the lower surface.

Flowers - 0.8 to 1.3 cm long, bright yellow, pea-like, occuring singly or in clusters of up to 9 (usually 3 to 7) in the leaf axils and at the end of branches. Flowering occurs mainly from late winter to spring, but can also occur towards the end of summer.

Fruits - Brown to black flattened pods, narrow-oblong in shape, 1.5 to 2.5 cm long, 5 mm wide, densely covered with long silky hairs. The pods appear in late spring and summer and coil after the seed is released.

Roots - Branched taproot with shallow lateral roots.

Seeds - Dark-brown to black, smooth, rounded and slightly flattened, 2 to 3 mm diameter, 5 to 8 per pod.

Similar Species

Cultivars, hybrids and closely related Genista species eg; Maderia broom, Genista stenopetala Webb & Berthel. (= G. maderensis), and G. racemosa L. are utilised in horticulture as ornamentals. Some appear to have become naturalised and have potential for further spread. A small infestation of Dyers broom, Genista tinctoria L. ssp. depressa (M.Bieb.) P.E. Gibbs, has been recorded at Buckleys Falls, near Geelong. A hybrid G. monspessulana X G. sp. developed by the nursery trade is naturalised in Victoria at Langwarrin.

Flax-leaved broom, Genista linifolia L., is also a declared weed in Victoria. It can be distinguished by its stalkless or nearly stalkless leaves which have rolled edges and are densely hairy on the underside.

The Problem

Cape broom is capable of forming dense thickets on grazing lands, in native vegetation and on roadsides, which exclude most other vegetation. Dense infestations of cape broom provide harbour for rabbits and foxes and increase fire fuel-loads in native vegetation and agricultural areas. In native vegetation, cape broom excludes desirable indigenous species. Cape broom is considered toxic to stock if grazed excessively, but in Australia no cases of poisoning have been reported. Fire stimulates seed germination by breaking the dormancy of soil-stored seed resulting in dense infestations of seedlings. However a small percentage of seed are not dormant and are capable of germinating immediately on exposure to suitable temperature and soil moisture conditions. This variation in seed dormancy and germination increases the difficulty of control.

Dispersal

The seeds of cape broom are ejected with considerable force from the pod when it opens and may be dispersed several metres from the parent plant. Seeds may also be dispersed locally by ants. Road graders and earth moving equipment are probably the most important agents in longer-distance seed movement. Other means of seed dispersal include slashing, water, farm machinery and vehicles, contaminated agricultural products and animals moving through infested areas.

Management Program

Some control methods described in this note are only effective if used in combination with other control options as part of a long-term management program.

If used in isolation, these methods do not effectively destroy the plant, allowing it to re-shoot or continue to grow. Authorised officers from DPI or DSE may direct landowners to undertake specific control activities to ensure methods are used that are capable of destroying plants and preventing their spread.

Figure 1. Cape broom.

Figure 2. Cape broom infestation.

Where directed to do so, landowners must use the method or methods as directed by the authorised officer. In most cases the landowner will be able to choose from a variety of options appropriate for use in their particular situation.

Management programs must be initiated in order to effectively control cape broom. In planning these programs integrated management strategies may achieve the best results.

New infestations of cape broom should be treated prior to plants reaching the flowering stage. Once plants begin seeding, control becomes more difficult and dispersal to other areas is likely. In native vegetation the avoidance of ground disturbances, particularly by vehicles and earth moving equipment, will reduce the rate of invasion of cape broom.

Treated areas should be regularly checked for regeneration, particularly after fire.

Hand-pulling
Small plants can be hand pulled in spring when the ground is soft. Large shrubs should be cut close to ground level and the stump painted with herbicide.

Slashing
Cutting seedlings when they are 5 to 10 cm high can provide effective control of regenerating plants. Thickets can be slashed with a brush cutter and any regrowth sprayed with herbicide.

Grazing
Sheep, goats and cattle eat cape broom, particularly younger seedlings, and may suppress the development of infestations. Larger plants may need to be cut or slashed to allow stock better grazing access.

Fire
Cape broom responds to fire in a similar manner to many Australian native plants. Soil-stored seed is stimulated to germinate following fire and may continue to germinate for up to 3 years following burning. Most adult plants are killed by fire, but some are capable of re-sprouting from the rootstock. Although soil-stored seed may be depleted by burning, effective control of cape broom can only be achieved by regular treatment of regenerating seedlings by hand-pulling, grazing or herbicide application for 3 to 5 years following fire.

Chemical Control
The Australian Pesticides & Veterinary Medicine Authority (APVMA) is responsible for the assessment and registration of agricultural and veterinary chemicals in Australia. As chemical products are registered on a daily basis and renewal of these registrations are undertaken each financial year, there is much change in the registration status of products each year. The information is available from APVMA (external link).

The Chemical Standards Branch (CSB) of the Department of Primary Industries provides information on agricultural chemicals registered in Victoria and their uses. Enquiries will be referred through the Customer Service Centre on 136 186. Information can also be obtained by visiting the CSB website.

Under Victorian legislation there are controls on the use of agricultural chemicals. It is the responsibility of the user to be familiar with these controls. These responsibilities are outlined in Information Note AG0520: “Responsible use and handling of farm chemicals”.

Farm chemicals are registered for specific uses. Each chemical has a ‘product label’, which documents the approved use and the approved rate of use within each State of Australia. This label is important in determining the appropriateness of chemical use.

Choose only products registered for use on cape broom in your particular situation. Read the product label carefully and follow all label instructions.

Your chemical retailers can provide information on registered chemical products that are available in their store. They can also supply a ‘material safety data sheet’ that outlines the health and safety issues associated with use of a product.

Legal use of some restricted chemicals requires the user to possess an Agricultural Chemical User Permit (ACUP). Other chemicals have restrictions on their use in Agricultural Chemical Control Areas (ACCAs).

Information on ACUPs, ACCAs and other chemical information can be found at the CSB website.

Use a product containing active constituents that is registered for use in Victoria to control cape broom in the particular situation in which you need to use chemical control, eg. in non-crop areas. Consult the product label for detailed information.

Biological control
Cape broom, Madiera broom and flax-leaved broom have been nominated as targets for biological control. Testing and evaluation of potential biological control agents will take a number of years.

Further Advice

Contact your local landcare or friends group for further assistance and advice.
Call the DPI/DSE Customer Service Centre on 136 186.
Visit the DPI website
Weeds Australia (external link)

References

Jeanes, J.A. (1996) Genista. Pp. 827-829 in Walsh, N.G. and Entwisle, T.J. (Eds.) Flora of Victoria Volume 3 Docotyledons, Winteraceae to Myrtaceae. Melbourne, Inkata Press.

Parsons, W.T. and Cuthbertson, E.G. (1992) Noxious Weeds of Australia. Melbourne, Inkata Press.

Acknowledgments

Prepared by Ross Williamson, 1997. Updated by Ian Faithfull. Updated by Melanie Martin, DPI, October 2006. Chemical information supplied by Chemical Standards Branch August 2006. Updated by Greg Johnson, DPI September 2007.

The advice provided in this publication is intended as a source of information only. Always read the label before using any of the products mentioned. The State of Victoria and its employees do not guarantee that the publication is without flaw of any kind or is wholly appropriate for your particular purposes and therefore disclaims all liability for any error, loss or other consequence which may arise from you relying on any information in this publication.

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