Invasive Aliens

Alien vegetation management

Invasive alien vegetation refers to plants brought to South Africa from other countries, both intentionally and unintentionally, that cause human, environmental or economic harm.

Without natural enemies, these plants reproduce and spread rapidly, taking valuable water and space from our indigenous plants. Many alien plants consume more water than local plants, depleting our valuable underground water resources. Dense alien vegetation can also provide plenty of fuel for veldfires, making them exceptionally hot, which damages the burnt area’s soil structure.

Invasive alien plants are a major threat to biodiversity in catchment areas, potentially disrupting the delicate natural balance in ecosystems. As we depend on biodiversity for water, food, wood, clean air, medicine and much more, it is vitally important that we protect this resource.

The top 10 invasive alien plants affecting the Western Cape are:

  1. Rooikrans
  2. Black wattle
  3. Port Jackson
  4. Silky hakea
  5. Long-leafed wattle
  6. Stinkbean
  7. Australian myrtle
  8. Spider gum
  9. Cluster pine
  10. Blackwood

These plants can have a severe effect on water resources, reducing water run-off by as much as 30% in heavily infested areas.

CapeNature provides invasive alien vegetation management to ensure a sustainable water supply and to make cleared land productive again. We use cleared invasive plants productively, for example, making furniture.

Through our alien-vegetation removal programme, we train people from local disadvantaged communities in plant identification, chainsaw use, health and safety, herbicide use, personal finance, nutrition, drug awareness, site management, educating peers, and field safety and survival.

How to control invasive alien vegetation 

Biological – Some alien plants have natural enemies, such as insects and diseases that only affect a specific species. The controlling agents (beetles, viruses) are sourced from the country of origin and released here among an invasive species to control it.

Manual – Young or small invaders can be removed from the soil with your hands. The plants should be stacked responsibly to prevent regrowth.

Mechanical – Plants and trees can be chopped down with a hatchet, panga, bowsaw or chainsaw. Trees can also be killed by removing a 30–40cm strip of bark around their trunks (known as “ring-barking”). This prevents food going to the leaves and kills the tree.

Chemical – Two or more methods can be used at the same time. For example, ring-barking and then spraying a registered herbicide on the stump.

How can you help?

  • Learn how to identify, control and remove invasive alien plants
  • Educate others
  • Join or form a hacking team to control alien plants in your area
  • Remove the plants when they are still small
  • Replace alien plants with indigenous ones
  • Plant only indigenous, water-wise plants in your garden.

Please help us clear these invaders and conserve our water resources for future generations.