Environment

Pampas grass

Pampas grass.Pampas grass.

Common name:
Pampas grass
Purple pampas grass

 

Scientific name:
Cortaderia selloana
Cortaderia jubata

 

Regional classification:
Only boundary control adjacent to roadside and could be enforced if roading authority has an active control programme in place

 

National classification:
National Pest Plant Accord – banned from being sold, propagated or distributed

Description

There are two species of pampas in Northland:

  • Pampas grass - Cortaderia selloana
  • Purple pampas grass - Cortaderia jubata

PAMPAS GRASS

Common pampas is a perennial grass species usually erect and dense, forming stands up to six metres high.

 

Flowers:

  • colour variable, generally white, pinkish or purple
  • fluffy hairs (female) or hairless
  • appear from mid-March to May

PURPLE PAMPAS

Purple pampas is similar but very uniform and forms stands up to three metres high. 

 

Flowers:

  • flowering stems mainly purple, fading to dull brown
  • only female with fluffy hairs
  • appear late January to mid-March
  • seed sets without the need for pollination

Why is it a problem?

Pampas grass is a very invasive plant, forming dense and often impenetrable stands. As it spreads, other desirable vegetation is smothered.

 

Pampas grass poses a fire risk in summer, is home to rats and mice and affects visibility on roadsides.

 

The seeds of the plant can also affect the quality of exported products like kiwifruit. The range of areas under threat includes forests, conservation areas, particularly scrublands, reserves and roadsides.

Native species

Pampas grass is often confused with native toetoe. There are four native species:

  • Cortaderia fulvida
  • Cortaderia richardii
  • Cortaderia splendons
  • Cortaderia toetoe

There are several key differences between the introduced pampas species and the native species.

 

Native toetoe.Native toetoe.

The leaf bases of all the native species are coated in a white, waxy surface which is a reliable means of distinguishing them from pampas.

 

The leaf blades of toetoe have fine secondary veins parallel to the midrib which are a characteristic feature of the native species.

 

Dead leaves drop but do not form a spiral in the native species. Introduced pampas will often be surrounded by these dead leaves which resemble wood shavings.

 

Introduced pampas leaves snap readily when given a sharp tug. Native species do not snap readily.

What can I do?

Learn to identify pampas species and distinguish them from the native toetoe.

 

Clear all pampas from your section, farm or other property. 

Your responsibility

Pampas grass is an introduced species and a pest plant in Northland. It cannot legally be propagated or distributed. In addition the Northland Regional Council may require control measures to be taken by land occupiers.

 

The long-term goal is to control the spread of pampas grass particularly into highly productive lands or areas with high ecological and recreation values.

Recommended control suggestions

Site management:

  • Establish that species is not native toetoe.
  • Control before seeding when possible.
  • Young pampas grass plants can be dug or pulled out when they are small.
  • Always use most selective method.
  • Plan for increased fire risk after control. Do not burn at any stage.
  • Large infestations can be grazed by cattle as long as toetoe is not present.
  • Pampas recedes as shade increases, so encourage weed replacement (planting, regeneration).

  • Cleared areas should be mulched or quickly revegetated to stop reinvasion by wind-blown pampas seed.

Recommended approaches:

  1. Grub out small to plants. Remove large plants with digger.
  2. Weed wipe all year round (200ml glyphosate + 2ml penetrant/1L).
  3. Spray summer-autumn (150ml haloxyfop (selective) + 50ml crop oil/10L).
  4. Spray (summer-autumn) dense sites where non-target damage is unlikely (100ml glyphosate (non-selective) + 20ml penetrant/10L).

Caution: When using any herbicide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.

More information

For further information or control advice please contact one of our Biosecurity Officers at the Northland Regional Council on 0800 002 004:

  • Whangarei: Ken Massey
  • Dargaville: Peter Joynt
  • Kaitaia: Doug Foster
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