Spiny Emex Control Guide

Spiny emex plant with fruits, image: Rod Randall, The Plant Protection Society of Western Australia 


  • Plan your control program, this will save time and money in the long-run;
  • Consider the impact of your control methods on off-target species, especially if herbicides are used;
  • Ensure machinery and equipment is washed down between sites or prior to contractors leaving site;
  • Get in early - for new infestations, eradicate before the plants reach the flowering stage: once plants begin seeding, control becomes more difficult and expensive;
  • Carefully time your use of herbicide for best results (see Herbicides for Spiny Emex Control for more information);
  • Coordinate your control program with neighbouring landholders where your weed problem crosses property boundaries;
  • Revisit and regularly inspect the site and ensure follow-up is undertaken;
  • Use a combination of different control methods;
  • Establish vigorous pasture (or native species) after removal to reduce re-infestation; and
  • If drought feeding use a defined drought feedlot area to limit potential introduction of the weed and aid future control.


  • Don't introduce spiny emex to spiny emex-free areas (e.g. by failing to wash down machinery and equipment between sites);
  • Don't start your control program without first planning your approach;
  • Don't allow spiny emex to flower and set seed before treatment;
  • Don't rely on one attempt at removal - follow-up is essential; and
  • Don't rely on just one control method.

Spread of spiny emex

  • Spiny emex reproduces by seed.
  • The fruit is well adapted for dispersal, with the spines attaching to shoes, tyres, the feet of animals and containers of produce.
  • Spiny emex fruit can be spread as a contaminant of fodder and agricultural seed, as well as by water along watercourse and during floods.
  • The fruit can live for 4 years in the soil.

Avoid the introduction of spiny emex

  • Avoid the use of fodder and poorly graded seed from infested areas which may contain spiny emex fruits.

Physical removal

  • Isolated plants can be grubbed. Because fruit can develop at an early age, aim to remove all plants shortly after emergence.
  • Follow up control is required as seedlings continue to appear for several years.


  • Cultivation will kill seedlings. However due to the length of the germination period, cultivation needs to be used in conjunction with herbicide treatment.
  • Start with a shallow cultivation in late summer to encourage as much germination as possible after autumn and early winter rains.
  • Continue to cultivate while controlling any emerging spiny emex with herbicide.
  • Avoid deep ploughing as this buries seed, which can be brought back to the surface to grow in later cultivations.

Chemical control

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