Broom

English broom (Cytisus scoparius), flax-leaf broom (Genista linifolia), and Montpellier broom (Genista monspessulana)
Montpelier broom in flower                                                
Image above: Montpellier broom in flower, © RMC.

​What is broom?

  • Widely cultivated across Australia for ornamental purposes, brooms are significant environmental weeds that invade native vegetation, plantation and pastoral systems in Australia causing significant environmental and economic impacts, capable of completely transforming invaded habitats.
  • Three species are recognised as Weeds of National Significance (WONS): English (or Scotch) broom (Cytisus scoparius), flax-leaf broom (Genista linifolia), and Montpellier (or Cape) broom (Genista monspessulana).
  • These species are all present in Tasmania, each a declared weed under the Tasmanian Weed Management Act 1999. The importation, sale and distribution of English broom, flax-leaf broom, and Montpellier broom are prohibited in this state.

How to identify broom

  • English, flax-leaf, and Montpellier broom are small to medium sized shrubs which can grow up to a height of 3 m. The leaves are trifoliate, (each leaf divided into 3 leaflets), with the central leaflet being longer than the outer two leaflets.
  • Leaflets and young stems of flax-leaf broom are covered in woolly, grey hairs, giving the plant a silvery look when viewed from afar.
  • Broom flowers are bright yellow, growing in dense clusters at branch ends, appearing late winter to late spring.
  • Brooms grow quickly, produce large amounts of seed in pods, and can tolerate diverse environmental conditions. When the seeds are mature and still attached to the parent plant, the pods open explosively to eject the seed up to 3 metres.
  • Brooms establish rapidly after disturbance such as fire or grazing, but can also invade relatively undisturbed areas.
  • If not controlled, brooms can modify native ecosystems by increasing the frequency and intensity of fire, changing vegetation structure, altering soil chemistry and providing harbour for invasive animals.
  • Although effective control measures for broom exist, its ability to rapidly re-establish from a persistent seed bank necessitates intensive follow-up.
  • For further information or help in identifying English broom, flax-leaf broom, or Montpellier broom, refer to the Commonwealth government WONS web site, Weeds of National Significance – Broom.
  • For help in identifying English broom, flax-leaf broom, or Montpellier broom, also search the Dennis Morris Weeds and Endemic Flora Database for broom illustrations. If you are still in doubt about the weed you are dealing with, contact Biosecurity Tasmania on 03 6165 3777 for help.

Close up of seed pod of English broom, photo:  Matthew Baker English broom invading bushland, photo: Matthew Baker English broom, photo: Marty Bower
Montpellier Broom close  up, photo:  Matthew Baker Montpellier broom, flower close up, Photo: Matthew Baker Montpellier broom, photo: Matthew Baker
Images top row, L-R: English broom seed pod, invading bushland, (© Matthew Baker); & English broom flowers, (© Marty Bower).
Images bottom row, L-R: Montpellier broom leaves, flowers, flower close-up, & invading bushland, (© Matthew Baker).

Broom in Tasmania

  • A shrub in the pea family, (Fabaceae), broom is native to Europe and the western Mediterranean. Widely naturalised on mainland Australia, brooms occur in New South Wales, Victoria, South Australia and Western Australia.
  • Brooms were originally introduced to Tasmania as garden plants.
  • English broom occurs throughout the settled areas of the state, being locally abundant on roadsides, waste areas, poor quality pastures and in disturbed bushland.
  • Montpellier broom is widely distributed in Tasmania's north, north-east and in the south.
  • Flax-leaf broom is known to be naturalised in several locations in the south and north-west. Given time, this species could become more common as an invader of bushland, roadsides and disturbed sites throughout Tasmania.
  • Broom can form dense thickets in degraded pasture and reduce productivity and access. Broom along roadsides can reduce visibility and increase road maintenance costs. Dense thickets of broom can also provide cover for pest animals such as rabbits.
  • Broom also invades a wide range of native vegetation including native grassland, woodland/open forest and subalpine grassland, where it competes with native plants and alters fauna habitat.
 

 


Images above, L-R: flax-leaf broom dried seed pods, (© ALA, Jackie Miles); flax-leaf broom mature plant in bushland, (© QBIT, Uni of Q'ld); flax-leaf broom flowers, (© Xemenendura, Wikimedia).

Legal status of broom in your area?


See also

Statutory Weed Management Plan - Montpellier broom
Statutory Weed Management Plan for English broom
Useful Weed Resources

Other useful links

Pest Genie
APVMA

Broom Control Guide

Do

  • Plan your control program, this will save time and money in the long-run;
  • Consider the impact of your control methods on off-target species, especially if herbicides are used;
  • Ensure machinery and equipment is washed down between sites or prior to contractors leaving site;
  • Get in early - for new infestations, eradicate before the plants reach the flowering stage: once plants begin seeding, control becomes more difficult and expensive;
  • Carefully time your use of herbicide for best results (see Herbicides for Broom Control for more information);
  • Coordinate your control program with neighbouring landholders where your weed problem crosses property boundaries;
  • Revisit and regularly inspect the site and ensure follow-up treatment is undertaken;
  • Use a combination of different control methods; and
  • Establish vigorous pasture (or native species) after removal to reduce re-infestation.

Don't

  • Don't introduce broom to broom-free areas (e.g. by failing to wash down machinery and equipment between sites);
  • Don't start your control program without first planning your approach;
  • Don't allow broom to flower and set seed before treatment;
  • Don't rely on one attempt at removal - follow-up is essential;
  • Don't rely on just one control method;
  • Never burn broom without follow up treatment of regrowth; and
  • Do not burn broom in native vegetation.

Spread of broom

  • Broom spreads solely by seed. The bursting pods can eject seed for 1 to 3 metres from the parent plant. Ants may also disperse seeds. Dry pods containing seeds can also be blown short distances by wind.
  • Broom seeds are not buoyant in water but can be carried in the bed load of rivers and streams, resulting in long distance dispersal downstream. Long distance seed movement can also occur in mud and soil carried on road graders and earth moving equipment, farm machinery, vehicles and footwear and in sand and gravel from quarries.
  • Seed can also be carried within the digestive tracts of horses and other animals. Contaminated agricultural produce may also result in some spread.
  • Germination usually occurs after some soil or vegetation disturbance including cultivation, fire, slashing, herbicide treatment, road-making and pig-digging. However, broom can also invade native vegetation without major disturbance.

Avoiding the introduction of broom

  • If cultivation must be carried out in infested areas, ensure all equipment is cleaned and checked for broom seed before moving to un-infested areas. If possible, always work un-infested areas first.
  • Gravel and sand should not be removed from infested quarries and streams.
  • Broom growing along access tracks must be controlled to limit spread of seed. Vehicles, bush walkers and horse riders using infested areas should keep to designated routes to minimise the spread of seed.

Physical removal

  • Small or isolated plants can be hand pulled or grubbed in spring when the ground is soft; a beneficial approach when working in high value native vegetation.
  • Cutting seedlings when they are 5 to 10 cm high can provide effective control of regenerating plants.
  • Larger shrubs should be cut close to ground level and the stumps painted with herbicide.
  • Dense thickets can be slashed with a brushcutter and regrowth sprayed with herbicide.
  • In large infestations with an established seed bank, cut stems bearing viable seed should be left on-site to prevent accidental spread.
  • See Herbicides for Broom Control for more information.

Cultivation

  • Pasture improvement is the best method of control for broom infested pastures on arable land where large plants can be mechanically removed, followed by repeated cultivation, pasture establishment and grazing.
  • Some dense infestations have been destroyed by bulldozing and repeated cultivation over two years. However, soil disturbance will move seed from the surface and distribute it through the soil profile and may in some instances make long term eradication more difficult, so follow-up control will be necessary.
  • In accessible areas, (eg, plantations or pastures), equipment can be used to mulch large, non-seeding broom infestations. The layer of mulch may suppress broom germination and regrowth temporarily, thereby assisting with follow-up measures.
  • Ensure machinery and footwear is cleaned and free of soil prior to leaving the site. Avoid driving vehicles or machinery through infestations when seed pods are present, as they can explosively release seed that may lodge on vehicles.

Burning

  • Burning can be an effective first step in managing broom by removing above ground biomass and reducing the broom seed bank; (heating of the soil by fire can stimulate the germination of up to 90% of seed in the soil).
  • To prevent more infestations from developing, sustained follow-up control is required each year to kill re-sprouting plants and new seedlings.
  • Post-fire, hand weeding or herbicide application should be carried out as soon as ecologically feasible, but care is required to minimise herbicide impact on regenerating native species.
  • When pasture species cannot be established on burned areas (e.g. stony ground, creek banks), or regeneration of native species is required (conservation areas and bushlands), do not use fire to remove broom.
  • In heavily infested areas, wildfire contingency plans should also include broom management.
  • Note: Great care is needed when using fire. Appropriate conditions, equipment and experienced personnel are essential. The landowner is responsible for ensuring that all planned burning can be contained and is conducted in a safe manner. Prior to any planned burn being undertaken, the landowner must inform all relevant authorities and obtain all relevant permits. The Tasmania Fire Service is the responsible authority for granting fire-permits.

Grazing

  • Sheep and goats will graze broom seedlings and flowers and assist in preventing infestations.

Biological control

  • Biological control is the use of a living species, usually an insect, mite or disease, to control a weed.
  • Biological control will not eradicate broom, but may be used in conjunction with other control methods.
  • Biological control agents for English broom that have been released in Tasmania include the twig mining moth and the broom bud psyllid.
  • For more information on biological control programs in Tasmania contact the Tasmanian Institute of Agriculture.

Native vegetation

  • In native vegetation, preventing ground disturbance will help reduce the rate of invasion by broom.
  • Do not burn broom in native vegetation. Bushes should be removed with minimal soil disturbance.

Chemical control

  • A number of herbicides are registered for use on broom in Tasmania. See Herbicides for Broom Control for more information.
  • For dense stands wider than 4 to 5 metres, access paths should be cleared to allow complete coverage.
  • Apply herbicide when plants are actively growing. This is generally spring to early summer, and after the autumn break.
  • Young broom plants can be controlled relatively easily because of their low tolerance to herbicides. They should be controlled before they set seed, (less critical for established stands with a seed bank).
  • Allow regrowth to reach 50 to 100 cm high before herbicide treatment; this ensures enough leaf area to absorb sufficient herbicide to kill the roots.
  • Basal bark, drill and fill (stem injection), and cut stump applications are useful where foliar application of herbicide may cause off-target damage, for example in treating broom on riverbanks or amongst desirable shrubs and trees.
  • In agricultural situations, broom bushes should be removed after spraying to facilitate the preparation of a seedbed, the sowing of pasture seed and the spot treatment of regrowth. This removal will also reduce the fire hazard created by the dead plants.
  • Sprayed bushes should not be removed until full brownout has occurred (at least six months after treatment).

Herbicides for Broom Control

Herbicides for Broom Control


Important Disclaimer
To the extent permitted by law, the Tasmanian Department of Primary Industries, Parks, Water and Environment (including its employees and consultants) excludes all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using information or material (in part or in whole) contained on this website.


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