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Red cestrum (Cestrum elegans)

Red cestrum forms dense thickets and is poisonous to people, pets, livestock and native animals. It can also outcompete native plants and restrict movement of people and animals.

Key facts

Type: Weed, shrub.

Native to: Southern Mexico.

Established in: QLD, NSW, VIC, TAS, SA.

Other names: Elegant poison berry.

Best time to act: Look for flowers mainly from winter to spring, and treat mature plants before they flower.

Identification

  • A perennial shrub that can grow up to 5 m tall, with one or several stems at the base.
  • Most parts are covered in fine purple hairs, and older stems become woody.
  • Its alternate leaves are dull green above, paler underneath, oval to spear-shaped, and 7–11.5 cm long.
  • Pinkish red to pinkish purple tubular flowers grow in tight clusters, mostly from winter to spring.
  • The fruit are rounded red or pink berries, 6–13 mm in diameter.
  • Look-alike: Early flowering jessamine (Cestrum fasciculatum) looks similar but has larger flowers; hybrids of the two species also occur.

Where it grows

In NSW it has been found near Wollongong and the southern highlands, near Bellingen and Port Macquarie, in Newcastle and at several locations in Greater Sydney, growing in places such as rainforest edges, wet sclerophyll forests, waterways and paddocks.

Why it matters

  • All parts of the plant are toxic, especially the berries, and it can cause poisoning in people and animals.
  • Its poisonous alkaloids can cause animal deaths; livestock including cattle and horses are affected.
  • Dense thickets outcompete native plants and reduce food and shelter for native animals.
  • Infested pastures may be unavailable for grazing because of poisoning, and thickets can restrict movement.

How it spreads

  • Birds eat the fruit and spread seeds in their droppings; seeds can also travel downstream from plants beside waterways.
  • Seeds may be spread in contaminated soil or mud, and each plant can produce up to 1,500 seeds a year that remain viable for up to 8 years.
  • Stem and root fragments can grow into plants and may be spread by garden dumping; plants also sucker readily.

Control options

  • Wear gloves and protective clothing, and remove small seedlings by pulling or digging them out.
  • Spray actively growing plants, covering all foliage, or cut stems and apply herbicide within 15 seconds; use registered herbicides according to the label and any permit.
  • Dispose of plants carefully because stems can reshoot when left touching soil; contact your local council for disposal advice.
  • Control plants before flowering, follow up regrowth and new seedlings for many years, and keep livestock away until treated plants have disintegrated or been removed.

Hygiene and washdown

  • Avoid moving soil or mud that may contain seeds, and do not dump plant fragments where they can take root.
  • Dispose of cut plant material carefully and ask your local council for advice.
  • 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: Regional priority in 2 of 11 regions. Regional priority weed in North Coast, Northern Tablelands. 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: Permitted, not declared. Listed as a permitted organism in WA, so it can be brought in, but it is not a declared pest.
  • Tasmania: Not declared. Not a declared weed in Tasmania. Other laws may still apply.
  • 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.

  • Queensland: Biosecurity Act 2014 (Qld), administered by Biosecurity Queensland (13 25 23)
  • New South Wales: Biosecurity Act 2015 (NSW), administered by NSW Department of Primary Industries and Regional Development
  • Victoria: Catchment and Land Protection Act 1994 (Vic), administered by Agriculture Victoria
  • Tasmania: Biosecurity Act 2019 (Tas), administered by Biosecurity Tasmania
  • South Australia: Landscape South Australia Act 2019 (SA), administered by the regional landscape board

Sources