Broom - Scotch

NOXIOUS WEED:   Class 4

Cytisus scoparius

family: FABACEAE

Description

• Erect, woody perennial shrub to 3m from Europe, with ridged, much-branched stems, common in disturbed areas. Tolerates a wide range of soil conditions.   Also known as English and European Broom.
• Sparse, tiny grey-green leaves with three leaflets; older plants may be almost leafless.
• Large numbers of bright yellow pea flowers are borne singly or in pairs along the stems in spring.
• Black flattened pods with hairy margins produce huge numbers of hard brown shiny seeds, believed to survive 70 years or more in the soil.

Dispersal

Spreads by seed: pods eject seeds up to 4m from the plant (up to 6000 per plant per year). Seeds can also be spread by water, animals, mud on shoes or tyres, or in contaminated soil.

Impact on Bushland

Grows rapidly, competing aggressively with native plants. Forms dense stands and dramatically reduces biodiversity. Transforms the ecosystem into one dominated by weeds. Also a serious fire hazard.

Wentworth Falls: dense germination of Scotch Broom after soil disturbance - one season's growth!
photo: © Barbara Harley

Distribution

Upper Blue Mountains.

Alternative Planting

Native Plants
Native Dogwood (Jacksonia scoparia LM) 3m
Sunshine Wattle (Acacia terminalis) 2m
Golden Glory Pea (Gomphalobium latifolium);
other Gomphalobium species
native pea flowers (Pultanaea species)

Exotic alternatives:
Golden Bells (Forsythia viridissima)
Mexican Orange Blossom (Choisya)
Pieris
Azaleas

Control

Do not mow or slash. Spray, dig out or cut and paint when pods are green. Hand pull seedlings when soil is moist. Expect to hand-remove seedlings for years.

Scotch Broom and Small-leaf Privet completely dominate this railway embankment, seeding into the headwaters of Katoomba Creek
photo: © Barbara Harley

More Information

Weed of the Month article about Scotch Broom.

Scotch Broom is a Class 4 Noxious Weed.

Class 4 noxious weeds are plants that pose a threat to primary production, the environment or human health, are widely distributed in an area to which the order applies and are likely to spread in the area or to another area.

Control objective
Minimise the negative impact of those plants on the economy, community or environment of NSW.

Control action
The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority, and the plant may not be sold, propagated or knowingly distributed.

— NSW Noxious Weeds Act of 1993