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Besom heath (Erica scoparia)

Besom heath is one of the declared Erica weeds in Tasmania, where importation, sale and distribution are prohibited. It can invade pasture and native vegetation, and dense infestations can increase fire hazard.

Key facts

Type: Weed, shrub.

Native to: Introduced to Australia.

Established in: TAS.

Best time to act: Plants may be conspicuous in flower in winter and spring; slash only before flowering, and do not slash during or soon after flowering.

Identification

  • It is a long-lived shrub, generally 1.5 to 2 metres tall, and can occasionally reach 3.5 metres.
  • Its stems are woody and brittle, with narrow leaves arranged opposite one another or in whorls of three or four.
  • Erica flowers can be bell-shaped, tubular or globular, with four lobes.
  • After flowering, capsules containing numerous small seeds release them as the flowers brown.
  • Look-alike: Native heaths in the Styphelioideae subfamily can be confused with Erica; they generally have five petals and stiff leaves arranged alternately, rather than Erica's four flower lobes and opposite or whorled leaves.

Where it grows

In Tasmania, Erica species occur in degraded pasture, neglected areas and roadsides, and can invade wet and dry forest, grassland and riparian areas, generally where there has been soil disturbance.

Why it matters

  • In pasture, Erica can reduce productivity.
  • Dense infestations in native bushland can replace native species and alter the composition and diversity of native plant communities.
  • Erica is extremely combustible and increases fire hazard risk.

How it spreads

  • Erica reproduces by seed and stem layering; seeds can spread by wind, water, slashing, and in soil and mud.
  • Stems that contact moist soil can root, and plants can shoot from broken stems and roots.
  • Seeds can also be moved longer distances through planting, commercial cultivation or inadvertent transport of seed-containing soil.

Control options

  • Hand-pull or dig out seedlings and small plants, removing as much of the root system as possible.
  • Dispose of removed material carefully: burn it where appropriate or pile it where plants cannot layer; take care not to spread seed when disposing of flowering plants.
  • Slashing before flowering can reduce seed production but will not kill plants; slashing during or soon after flowering spreads seed and should not be done.
  • Use registered herbicides where appropriate, and follow up control because one attempt will not eradicate Erica.

Hygiene and washdown

  • Clean equipment and personnel using the Washdown Guidelines for Weed and Disease Control to reduce the chance of spreading Erica.
  • Avoid moving soil or mud that may contain seeds to new locations.
  • Inspect and clean vehicles, plant and footwear before leaving an infested area, paying attention to tyres, radiators, belly plates, tracks and floor mats.
  • Wash down at a designated bay where runoff is contained and can be monitored for seedlings.
  • Record each washdown so the client has evidence of clean entry and exit.

Classification by state

  • Australia (national): No national listing. Managed under state and territory law.
  • Queensland: Not prohibited or restricted. Not listed as prohibited or restricted matter in Queensland. Everyone must also take all reasonable and practical steps to minimise its risks (the general biosecurity obligation).
  • New South Wales: Not a priority weed. Not a state or regional priority weed in NSW. The general biosecurity duty applies: anyone dealing with it must prevent, eliminate or minimise the risk it poses.
  • Victoria: Not declared. Not declared under the Catchment and Land Protection Act 1994. Other Victorian laws may still apply.
  • South Australia: Not declared. Not declared under the Landscape South Australia Act 2019. Other laws may still apply.
  • Western Australia: Not listed. Not found in the Western Australian Organism List. Check with DPIRD before moving or keeping it.
  • Tasmania: Declared weed. Property managers are required by law to control declared weeds, and their import and sale are prohibited.
  • Northern Territory: Check NT list. There is no NT weed profile for it. Check the NT declared weeds list for its current status.
  • Australian Capital Territory: Not declared. Not declared under the Biosecurity Act 2023 (ACT). A general biosecurity duty still applies.

Legal obligations

Every state and territory places a duty on landholders and people working on land to prevent the spread of invasive species, such as the general biosecurity obligation in Queensland and the general biosecurity duty in New South Wales. Declarations and control requirements differ between states and local government areas, so check the current official list before work starts.

  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania

Sources