Rubber bush

Rubber bush is a declared Class B and Class C weed.

(Only declared Class B: South of 16°30' S latitude).

Another name for this plant is Calotropis procera.

Rubber bush - infestation 

Identification

You should use this as a guide. There may be other plants or weeds that look similar.

If you are unsure, contact the Weed Management Branch.

Habit

These features describe the habit of this plant:

  • small tree or spreading shrub
  • generally up to 4m tall
  • branches may shoot from the base of the plant.

Rubber bush - habit 

Stems and branches

These features can identify the stems and branches:

  • smooth and grey-green
  • covered with a soft, thick corky bark
  • bark can be brown to whitish.

Rubber bush - stems and branches 

Leaves

These features can identify the leaves:

  • large
  • opposite
  • rubbery
  • grey-green
  • 5 to 20cm long and up to 10cm wide
  • each pair of opposite leaves is at right angles to adjacent pairs
  • leaves do not have stalks, so appear attached to the stem.

Rubber bush - leaves 

Flowers

These features can identify the flowers:

  • purplish pink and white
  • five petals
  • waxy feel and appearance
  • grow in groups in the upper leaf forks.

Rubber bush - flowers 

Fruit and seeds

These features can identify the fruit and seeds:

  • fruit is green
  • 7 to 12cm long
  • rounded at the base and pointed at the tip
  • shaped like a mango
  • contains small seeds which have long silky hairs to aid dispersal.

Rubber bush - fruit and seeds 

Impact

Rubber bush can have all of the following impacts:

  • poisonous to humans and stock
  • can form dense thickets on disturbed and degraded soils
  • competes with native pastures and smothers native plants
  • inhibits access to watering points and restricts mustering.

Habitat and distribution

Rubber bush is native to tropical Africa and Asia.

It was probably introduced to Australia as a garden plant, or in the packaging of camel saddles brought from India in the early 1900s.

Rubber bush poses a significant risk to valuable grazing land in the NT. It has the potential to colonise large parts of the Barkly Tablelands and Victoria River District, where it competes with native pastures.

Rubber bush first became established in the Katherine area and then spread along the Roper River in the early 1950s. It has now spread into Western Australia and through the Barkly Tablelands to Tennant Creek.

Spread prevention

Rubber bush seeds are spread by wind and by attaching to animals, clothing and vehicles.

You can prevent the spread of rubber bush by doing all of the following:

  • map infestations to help develop a management plan
  • control minor infestations, isolated outbreaks or seedlings first
  • remove single plants immediately as one plant can create a thick stand in a few years
  • designate wash down areas and actively work to prevent contamination of clean areas
  • check vehicles, clothes and animals for seeds
  • monitor areas that you have treated and watch for re-infestations.

Rubber bush - spread 

Control

Rubber bush is difficult to remove physically. Chemical control together with maintaining the pasture to prevent re-invasion is the best way to control this weed.

Chemical control

The best time to treat rubber bush is from October to March. Below is a list of treatment methods that can be used.

Chemical and concentration Rate Situation, method and notes
Triclopyr 300g/L + Picloram 100g/L
Conqueror®
+ Aminopyralid 8g/L
Grazon™ Extra
750ml/ 100 L (water)
500-750ml / 100 L (water)
Seedling (individuals or infestation):
Foliar spray. Check label for recommended adjuvant product. More effective on plants < 2m as thorough coverage on all leaves is required.
Triclopyr 240g/L + Picloram 120g/L
Access™
1 L / 60 L (diesel)
1 L / 10 L (diesel)
1 L / 60 L (diesel)
Adult (individuals and infestation):
Basal bark < 5cm stem diameter. Spray all stems. Spray to point of runoff.
Thin line up to 5cm stem diameter
Cut stump > 5cm stem diameter
Tebuthiuron (200g/kg)
Graslan - Pending registration. Please check with Weed Management Branch for status confirmation.
1.5-2 g/m2 Seedling or adult:
Application to black clay soils in conjunction with seasonal rainfall. Spread granules according to density of the infestation.
Fluroxypyr (333 g/L)
Starane™ Advanced
3 L / 100 L (diesel) Adult:
Cut stump method for plants up to 10cm diameter and 3m high.

Rubber bush - foliar sprayRubber bush - basal bark

Last updated: 27 June 2017