Flax leaf, Montpellier and Scotch brooms

Native to the Mediterranean and north Africa, flax leaf, Montpellier and Scotch brooms are shrubs of the pea family with flexible broom-like young branches. They were introduced into Australia mainly as ornamental plants and also used in soil stabilisation and erosion control for mines and quarries. They occur in all Australian states and territories except Northern Territory and are listed as Weeds of National Significance.

Flax leaf, Montpellier and Scotch brooms are restricted invasive plants under the Biosecurity Act 2014.

Scientific name

Genista linifolia, G. monspessulana, Cytisus scoparius

Other names

Scotch can be called English broom ; Montpellier can be called Cape broom

Description

  • Woody shrubs, erect up to 1-4m tall.
  • Stems are green, 5-sided.
  • Leaves have 3 leaflets.
  • Flowers are bright-yellow, 2cm long.
  • Seed pods are pea shaped, narrowly oblong, 2-7cm long, hairy.
  • Lack thorns.

Habitat

  • Prefers light to medium, moist, well-drained soils.

Distribution in Queensland

  • Not found in Queensland, except Montpellier broom which is recorded in South East Queensland.

Life cycle

  • Flowers from late winter and produces as mass of long lived seeds.
  • Each plant can produce over 15,000 seeds per year.
  • Seed banks can survive more than 20 years.
  • Brooms can also regenerate from damaged stems.

Impacts

Environmental

  • Invades and shades out native bushland.
  • Increases risk of fire and changes soil chemistry.

Economic

  • Invades pastures and forestry plantations.

How it is spread

  • Spread by seed.
  • Broken branches can re-sprout.

Control

Effective control can be achieved by combining mechanical and herbicide treatments or by herbicide treatment alone. Choose control methods to suit your particular situation. All treated areas must be periodically checked and any regrowth treated, or initial treatment efforts will be wasted. Follow-up must be undertaken to ensure a successful control program.

Mechanical control

  • Hand-pull individuals.
  • Cut down larger plants.
  • Burn all stems and braches (if permitted) to destroy seed pods.

Fire

  • Burning can be an effective first step in controlling broom.

Herbicide control

Foliar spray
  • Spray all the plant with approved herbicide. Repeat spraying will be required.
Cut stump treatment
  • Cut stems horizontally as close to ground as possible and immediately (within 15 seconds) swab or spray cut surfaces and associated stem with herbicide mixture.
Stem injection treatment for stems greater than 5cm
  • Drill holes 5cm apart around the stem angled downwards and immediately fill with herbicide.

See the WONS brooms management guide for herbicide control and application rates.

Biological control

  • Five agents have been released in southern states with some success: broom seed bruchid (Bruchidius villosus), Scotch broom psyllid (Arytainilla spartiophila), Cape broom psyllid (Arytinnis hakani), broom gall mite (Aceria genistae) and broom twig mining moth (Leucoptera spartifoliella).

Legal requirements

  • Flax leaf, Montpellier and Scotch brooms are restricted invasive plants under the Biosecurity Act 2014.
  • All sightings of these weeds must be reported to Biosecurity Queensland within 24 hours of the sighting.
  • By law, everyone has a general biosecurity obligation (GBO) to take all reasonable and practical steps to minimise the risk of spread of the plant until they receive advice from an authorised officer.
  • It must not be kept, moved, given away, sold, or released into the environment without a permit.

More information