Cape Broom

(Also known as Montpellier Broom)

Genista monspessulana

Family: Fabaceae

Type of weed:

Flower colour(s):

Priority Weed State Priority Weed. (See more weeds of the class.)

Flowering Months: , , , , ,

Description

Cape Broom is a woody perennial shrub with many branches to 3–4 m. The plant remains green and leafy throughout the year.

Leaves are small and have three leaflets, 5–20 mm long.

Yellow pea flowers are very numerous, 8–12 mm long, appearing in clusters on the ends of the branchlets during spring and summer.

The seed pod is brown and densely hairy, 15–25 mm long, containing six or seven hard black shiny seeds.

Don’t confuse with…

Large plants can be confused with native pea plants such as Gompholobium because of similarities with the flowers and flowering times.

Small plants of Broom Spurge (Ampera xiphoclada) can be confused with this weed because they both have angular stems. The Broom Spurge stem is three-sided; Broom is four-sided (or square) in cross section.

The leaves and habit of Raspwort (Gonocarpus teucrioides), when less than 0.5m, can also look similar.

Dispersal

Pods eject seeds up to 4 m from the plant (up to 6,000 per plant per year). Seeds can also be spread by water, animals, or in contaminated soil. Fire or soil disturbance stimulates prolific germination.

Impact on bushland

Cape Broom competes with native plants, often forming a monoculture, leading to a loss of biodiversity. It produces seed which is long lived.

Distribution

, . Mainly the Lower to Mid Mountains.

Alternative planting

Native plants

  • Sunshine Wattle (Acacia terminalis)
  • Red Stemmed Wattle (A. myrtifolia)
  • (Breynia oblongifolia)
  • Yellow Pittosporum (Pittosporum revolutum)
  • Australian Indigo (Indigofera australis)
  • Native Dogwood (Jacksonia scoparia)
  • Golden Glory Pea (Gompholobium latifolium)
  • Native Pea flowers (Pultenaea spp)

Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.

There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.

Control

  • Hand remove
  • Stem inject or frill
  • Cut and paint

Manual control

Hand remove

Grasp stem at ground level. Rock weed backwards and forwards to loosen roots, then pull out gently. Carefully tap the roots to dislodge attached soil. Replace disturbed soil and pat down.

Considerations
  • Leave weeds so that roots do not make contact with soil; on a rock, for instance. A small amount of debris may be hung in a tree or removed from the site.
  • Vary the position of your body to avoid fatigue when removing plants by hand over extended periods.

Chemical control

Note: Herbicides that may be used for this weed include Glyphosate, Triclopyr.

Stem injection or frilling

Stem injection
Drilling holes at 45° and squirting poison into holes
Apply poison immediately after drilling

At the base of the tree, drill holes at a 45° angle into the sapwood (just under the outer bark) at two finger space intervals around the entire base of the tree. Repeat this process below the lowest branch

Frilling

As an alternative to drilling, make cuts into the sapwood with a chisel or axe. Fill each cut/hole with herbicide immediately. Repeat the process at 3 cm intervals around the tree.

Considerations

Plants should be healthy and actively growing. Deciduous plants should be treated in spring and autumn when leaves are fully formed. For multi-stemmed plants, inject or chip below the lowest branch or treat each stem individually. Herbicide must be injected immediately before the plant cells close (within 30 seconds before translocation of herbicide ceases.)

Cut and paint

Applying poison to cut stump from squeeze bottle
Apply poison immediately after cutting

Useful for small to medium sized woody weeds up to 10 cm in diameter.

Make a horizontal cut as close to the ground as possible with secateurs or loppers, and immediately apply concentrated Glyphosate to the exposed stump surface. Do not allow the surface to get covered with soil.

Specific control tips for this weed

Follow-up is needed as germination of seeds stored in the soil will be stimulated by the removal of existing plants.

For key points on these techniques:

State Priority Weed

Control measures:

  • The plant must be eradicated from the land and be kept fully and continuously suppressed and destroyed; and the land must be kept free of the plant.
  • If the weed is part of a new infestation of the weed on the land, notify the local control authority as soon as practicable.