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Bicolored heath (Erica discolor)

Bicolored heath is an introduced garden plant and a declared weed in Tasmania, where its importation, sale and distribution are prohibited. It is an environmental and pasture weed, and is one of the seven Erica species known to have populations in Tasmania.

Key facts

Type: Weed, shrub.

Native to: South Africa.

Established in: VIC, SA.

Other names: Bi-coloured heath.

Best time to act: Look for flowering plants in winter and spring, and undertake any slashing before flowering because slashing during or soon after flowering spreads seeds.

Identification

  • It is a long-lived, woody shrub, generally 1.5 to 2 metres tall and occasionally reaching 3.5 metres.
  • Its narrow leaves are opposite or arranged in whorls of three or four.
  • Flowers have four lobes and may be bell-shaped, tubular or globular.
  • After flowering, capsules contain numerous small seeds, released as the flowers brown off.
  • Look-alike: Native Australian heaths may look similar, but generally have five petals and stiff leaves arranged alternately, rather than the four-lobed flowers and opposite or whorled leaves described for Erica.

Where it grows

In Tasmania, Erica species occur on degraded pastures, neglected areas and roadsides, and can invade wet and dry forest, grassland and riparian areas, generally where soil has been disturbed.

Why it matters

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

How it spreads

  • It reproduces by seed and stem layering, which occurs when stems contact moist soil and develop roots.
  • Seeds can spread short distances by wind, water, slashing, vehicle draught and movement of soil or mud.
  • Long-distance spread can result from garden planting, commercial cultivation or inadvertent transport of soil containing seeds.

Control options

  • Hand-pull or dig out seedlings and small plants, removing as much of the root system as possible; dispose of removed material safely by burning where appropriate or piling it where it cannot layer.
  • Use weed matting where suitable; it can kill Erica and achieve a 100% kill after 45 weeks.
  • Cultivate infested pasture regularly until plants no longer resprout from root fragments, and establish competitive pasture species to help reduce regeneration.
  • Registered herbicides are available for Erica in Tasmania; follow approved methods and contact Biosecurity Tasmania for advice.

Hygiene and washdown

  • Clean soil and mud from equipment and personnel using the Washdown Guidelines for Weed and Disease Control to reduce the chance of spreading Erica.
  • 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.

  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board

Sources