Ageratum conyzoides

Preferred Scientific Name: Ageratum conyzoides

Often found as part of a mix of invasive flora, Ageratum conyzoides colonize cultivated and overgrazed tropical land. Once established, it is often rapidly replaced by a variety of woody weeds. Commonly referred to as billy goat weed, Ageratum conyzoides is native to South and Central America.

Ageratum conyzoides
Read more Down

Why is it a problem?

In favourable conditions, Ageratum conyzoides can carpet soil, often resulting in the displacement of crops. It is often found as part of invasive flora, which competes with arable crops, such as rice and maize. It is also a host plant of significant pathogens and nematodes, which can cause infection in crops like potato and banana. 


  • Displaces crops
  • Host plants to pathogens and nematodes
  • Loss of land
  • Reduces native biodiversity
  • Negatively impacts livelihoods

What’s the solution? 

Cultural control

Short periods of flooding provide effective control in Eucalyptus plantations in India. In field crops in the dry tropics, the density of the weed is reduced by minimum tillage systems.

Mechanical control

Ageratum conyzoides is shallow-rooted and relatively easy to control using mechanical means. As it is a prolific seeder, it is important to destroy plants before they flower.

Chemical control

A variety of herbicides have shown to be effective in protecting crops like maize, soyabean and tea from Ageratum conyzoides.

Fact file

Name Ageratum conyzoides


Asia, Africa, Americas and Caribbean, Oceania and Europe

For more information on distribution, view the full datasheet available here


Degraded pastures and cultivated areas

Natural enemies



High reproductive potential, highly mobile locally and benefits from mutilation

Likelihood of entry

High risk of accidental transportation



Plant Type


Further reading

Visit our online resource of research and full text articles and journals
Invasive Species Compendium

More invasive species

More Species