Green cestrum (Cestrum parqui)

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Impact

Green cestrum is a vigorous plant that can out-compete other vegetation. Green cestrum is toxic to animals including cattle, sheep, horse, pigs, poultry and humans. 

Toxicity

Green cestrum frequently causes ‘sudden death’ in livestock and is highly toxic to humans, capable of causing serious illness or death.

Although cattle are the most commonly affected animals, deaths have also occurred in goats, sheep, horses, pigs and poultry.

Green cestrum poison known as carboxyparquin causes severe liver damage and as a consequence survivors of cestrum poisoning experience elevated blood ammonia levels which then cause brain damage. Signs of poisoning in livestock include diarrhoea, abdominal pain, depression, disorientation, walking with a stagger, irritability, weakness, going off their feed, lying on the ground, and finally a period of coma or terminal convulsions.

Animals that have eaten green cestrum may die within hours or may remain sick for several days before they die. Often animals that appeared healthy 24 hours beforehand will be found dead for no apparent reason.

All parts of the plant are poisonous but as palatability is low it is not often eaten. Livestock poisoning usually occurs when other feed is scarce and animals are forced to eat cestrum, but spasmodic episodes of poisoning have been known to occur at other times.

Bushes that have been cut down or killed with herbicide will retain poison in their leaves, branches and berries. In fact, recently sprayed wilting plants are more palatable then fresh healthy plants and potentially can cause more deaths.

Livestock should always be removed from any paddock where a cestrum control program is under way and not returned until the leaf material has disintegrated or been removed.

In humans, poisoning causes liver damage, and all parts of the plant, especially the green berries are highly toxic if ingested. 

What to do if poisoning occurs:

  • If the patient is unconscious, unresponsive or having difficulty breathing dial 000 or get to the emergency section of a hospital immediately.
  • If the patient is conscious and responsive call the Poisons Information Centre on 13 11 26 or your doctor.
  • If going to a hospital take a piece of the plant for identification.

Distribution

Green cestrum was originally introduced into Australia from South America as an ornamental shrub for gardens. Since that time, it has become naturalised in areas of south-eastern Queensland, eastern New South Wales (NSW) and parts of Victoria and South Australia. 

In NSW, green cestrum is found in the Hunter Valley, the outer metropolitan areas of Sydney, the North Coast and the north-west, central west and south-west of the State.

Distribution map

Spread

Green cestrum originally spread from gardens where it was grown as an ornamental plant. It is spread most commonly in droppings from birds that have eaten the berries. Green cestrum seeds germinate mainly in autumn with young plants taking two or more years to flower and set seed. Mature plants will flower and seed each year. Green cestrum will sucker freely from its base if stumps are not treated after cutting. The plant will also grow from sections of the fleshy root which remain after a plant has been partly dug or pulled out.

Life cycle

Green cestrum seeds germinate mainly in autumn with young plants taking two or more years to flower and set seed. Mature plants will flower and seed each year. Seeds from these plants can remain dormant in the soil for many years. Established plants are semi-deciduous, losing most of their leaves during winter and producing rapid new growth in spring. Green cestrum will sucker freely from its base if stumps are not treated after cutting. The plant will also grow from sections of the fleshy root which remain after a plant has been partly dug or pulled out.

Description

Green cestrum is a medium-sized perennial shrub growing 2–3 m. It usually has many light-green, brittle stems.

Leaves

The shiny-green leaves are 20–30 mm wide and 80–100 mm long. They have smooth edges, are pointed at each end and are arranged alternately along the branch. The leaves produce a pungent, foul smell when crushed.

Flowers

Green cestrum flowers from late spring to autumn. The flowers are normally yellow but may have a green tinge. Flowers grow in clusters at the end of branches. The flowers produce an unpleasant perfume during the day but can smell quite sweet in the evening. Individual flowers are 20–25 mm long, and are trumpet-shaped – opening into five, six or seven small, triangular lobes.

Fruit

Clusters of shiny, black, egg-shaped berries 7–10 mm long are produced during summer and autumn. The berries each contain several wrinkled seeds which are about 3–5 mm long. The dark pulp of the berries will stain fingers a purple colour if they are squashed. Berries remaining on the bush during winter will shrivel and become dull black or grey.

Habitat

Green cestrum is normally found along watercourses and in non-crop areas where it usually grows in small to medium-sized thickets.

References

Griffiths N and Bourke C (2008). Green cestrum. Primefact 718. NSW DPI, Orange.  

Technical reviewers: George Wisemantel, Greater Taree County Council and Bruce Watt, Central Tablelands RLPB.

References

  • Croft, D and Holding, D. (2004) A community approach: Green Cestrum. Factsheet. Cooperative Research Centre for Australian Weed Management.

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Control

Total eradication of green cestrum requires a combination of control techniques and frequent follow up work. Once a single control event occurs green cestrum can have vigorous regrowth from stumps or roots not removed or from dormant seed in the ground. Monitor control areas for regrowth and if necessary retreat the area using another form of control. New infestations should be destroyed before they flower and produce berries.

Physical control

Green cestrum can be controlled by repeated cutting down, digging or pushing out by mechanical equipment. All the yellow roots must be removed and destroyed appropriately to prevent regrowth. The roots can be burnt.

Chemical control

Herbicides are often the most effective and economical way of controlling green cestrum. However, only a registered herbicide should be used to control green cestrum infestations. For a list of registered herbicides and application methods see the Noxious and Environmental Weed Control Handbook.

Take care not to contaminate watercourses near clumps of green cestrum. Also, ensure that spray drift does not affect desirable plants in areas being treated and that operators follow the recommended safety precautions when handling and using herbicides.

Mulch

Mulch can be used to suppress seedling growth after chemical or physical control. Mulch also retains moisture in the soil and provides protection for native plants that can be sown to replace the green cestrum plants.

Competition

After the removal of green cestrum plants, a vigorous pasture or appropriate native species should be established to compete with any green cestrum seedlings and regrowth.

Consult your local agronomist or council weeds officer for advice on suitable species and establishment methods for the situation.

 

Herbicide options

WARNING - ALWAYS READ THE LABEL
Users of agricultural or veterinary chemical products must always read the label and any permit, before using the product, and strictly comply with the directions on the label and the conditions of any permit. Users are not absolved from compliance with the directions on the label or the conditions of the permit by reason of any statement made or not made in this information. To view permits or product labels go to the Australian Pesticides and Veterinary Medicines Authority website www.apvma.gov.au

See Using herbicides for more information.


PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Roundup®)
Rate: 1 part glyphosate to 1.5 parts water
Comments: Cut, scrape and paint.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


PERMIT 9907 Expires 31/03/2020
Glyphosate 360 g/L (Roundup®)
Rate: 1 part glyphosate to 50 parts water
Comments: Spot spray.
Withholding period: Nil.
Herbicide group: M, Inhibitors of EPSP synthase
Resistance risk: Moderate


PERMIT 11427 Expires 30/06/2019
Triclopyr 600 g/L (Garlon® 600)
Rate: 1.0 L per 30 L of diesel
Comments: Basal bark application. DO NOT over treat as excessive run-off might affect adjacent trees and shrubs through root absorption.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


2,4-D 300 g/L + Picloram 75 g/L (Tordon® 75-D)
Rate: 650 mL per 100 L of water
Comments: Handgun application on actively growing bushes in full leaf.
Withholding period: 1-8 weeks (see label).
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Amitrole 250 g/L + Ammonium thiocyanate 220 g/L (Various products)
Rate: 1.1 L per 100 L of water
Comments: Handgun application on active growth, before flowering.
Withholding period: Nil
Herbicide group: Q, Bleachers: Inhibitors of carotenoid biosynthesis unknown target
Resistance risk: Moderate


Picloram 100 g/L + Triclopyr 300 g/L + Aminopyralid 8 g/L (Grazon Extra®)
Rate: 500 mL in 100 L of water
Comments: Apply from late spring to early autumn. Any regrowth and seedlings must be resprayed when 1 m high.
Withholding period: Where product is used to control woody weeds in pastures there is a restriction of 12 weeks for use of treated pastures for making hay and silage; using hay or other plant material for compost, mulch or mushroom substrate; or using animal waste from animals grazing on treated pastures for compost, mulching, or spreading on pasture/crops.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Picloram 44.7 g/kg + Aminopyralid 4.47 g/L (Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 240 g/L + Picloram 120 g/L (Access™ )
Rate: 1.0 L per 60 L of diesel
Comments: Basal bark application.
Withholding period: Nil
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 300 g/L + Picloram 100 g/L (Grazon® DS)
Rate: 500 mL per 100 L of water
Comments: Apply from late spring to early autumn. Any regrowth and seedlings must be resprayed when 1 m high.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


Triclopyr 600 g/L (Garlon® 600)
Rate: 170 mL per 100 L of water
Comments: Retreat regrowth the next season.
Withholding period: Nil.
Herbicide group: I, Disruptors of plant cell growth (synthetic auxins)
Resistance risk: Moderate


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Legal requirements

The content provided here is for information purposes only and is taken from the Noxious Weeds (Weed Control) Order 2014 published in the NSW Government Gazette, detailing weeds declared noxious in New South Wales, Australia, under the Noxious Weeds Act 1993. The Order lists the weed names, the control class and the control requirements for each species declared in a Local Control Authority area.

Area Class Legal requirements
Albury 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Balranald 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Bayside 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Bega Valley 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Bellingen 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Bland 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Blue Mountains 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Bogan 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Bourke 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Brewarrina 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Broken Hill 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Burwood 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Cabonne 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Camden 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Campbelltown 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Canada Bay 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Canterbury-Bankstown 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Carrathool 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Castlereagh Macquarie County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Central Coast 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Central Darling 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Central Murray County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Cessnock 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Clarence Valley 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Cobar 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Coffs Harbour 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Coolamon 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Cootamundra-Gundagai 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Cowra 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Cumblerland 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Dungog 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Eurobodalla 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Fairfield 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Federation 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Forbes 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Georges River 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Glen Innes Severn 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Goulburn Mulwaree 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Greater Hume 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Griffith 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Gunnedah 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Gwydir 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Hawkesbury River County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Hay 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Hornsby 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Hunters Hill 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Inner West 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Inverell 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Junee 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Kempsey 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Ku-ring-gai 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Lachlan 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Lake Macquarie 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Lane Cove 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Leeton 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Liverpool 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Liverpool Plains 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Lockhart 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Lord Howe Island 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Maitland 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Mid-Coast 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Mid-Western Regional 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Moree Plains 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Mosman 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Murray River (formerly Wakool) 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Murrumbidgee 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Nambucca 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Narrabri 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Narrandera 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Narromine 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
New England Tablelands County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Newcastle 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
North Sydney 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Northern Beaches 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Orange 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Parkes 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Parramatta 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Port Macquarie-Hastings 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Port Stephens 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Queanbeyan-Palerang Regional 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Randwick 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Rous County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Ryde 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Shoalhaven 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Snowy Monaro Regional 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Snowy Valleys 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Southern Slopes County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Strathfield 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Sutherland 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Sydney 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Tamworth Regional 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Temora 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Tenterfield 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Unincorporated Area of Western Division 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Upper Hunter County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Upper Lachlan 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Upper Macquarie County Council 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Wagga Wagga 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Waverley 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Weddin 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Wentworth 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Western Plains Regional 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Willoughby 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Wingecarribee 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Wollondilly 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed
Woollahra 3 Regionally Controlled Weed
The plant must be fully and continuously suppressed and destroyed

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For technical advice and assistance with identification please contact your local council weeds officer.
For further information call the NSW Invasive Plants and Animals Enquiry Line on 1800 680 244 or send an email to weeds@dpi.nsw.gov.au

Reviewed 2014