Spartina alterniflora, s. anglica and s. x townsendii

Spartina

Family: Poaceae

Origin: Europe, North and South America

Spartina growing in tidal waters.
Can handle being underwater in high tides as well as out of the water at low tide. Control is best undertaken at low tide so as not to put chemicals into the estuary water.

Regional Pest Management Plan (RPMP) status

  • Hauraki Gulf Controlled Area Notice pest
  • Whole region — Progressive containment, council delivered

View more about the RPMP statuses

General description

Erect, perennial, clump-forming grasses < 1 m tall. Rhizomes are fleshy. Note: Spartina is under Sustained Control in the Kaipara Harbour.

What you need to know

To help protect our environment, you must not breed, distribute, release or sell spartina within the Auckland region.

Within the Spartina control zone in the Kaipara Harbour:

  • You must not plant spartina, unless you are transferring an existing plant on your land to another location within the boundaries of the same property
  • You must destroy any spartina on land that you occupy if it has been planted in breach of the above rules and you are directed to do so by an authorised person.

Auckland Council will manage spartina at all sites where it is known to occur outside of the Kaipara Harbour zone.

If you see spartina outside of the Kaipara Harbour zone, please report it to Auckland Council at pestfree@aucklandcouncil.govt.nz.

Habitats

Saline wetlands, estuaries.

Dispersal

Vegetative spread from rhizome fragments, dispersed by water. S. anglica and S. alterniflora can set seeds, also dispersed by water. Human-mediated dispersal through deliberate plantings.

Impact on environment

Forms dense swards. Traps sediment, raising levels above the high tide mark and reducing large estuaries and shallow harbours to thin drains surrounded by rough pastures. Destroys intertidal zonation and habitat and smothers tauranga mātaitai shellfish beds. Can lead to immense biodiversity loss.

Control

Site management

Spray on an outgoing tide. Follow up each year in February and November.

Recommended approaches

Do not attempt to undertake control of this species (excluding Kaipara Harbour). Please report to Auckland Council.

Physical control

Method: Dig out.

Plant parts requiring disposal: All parts.

Disposal options: Remove to greenwaste or landfill.

Biocontrol

Biocontrol is currently not available for this species.

Community agrichemical control recommendations

Certified Handler/Experienced agrichemical user: Foliar spray with 200ml glyphosate green per 10L of water and 20ml penetrant in February and November. Foliar spray with 100ml haloxyfop-P-methyl per 10L of water.

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Spartina growing in estuary.
A small clumping grass that grows in the muds of estuaries. Forms fleshy rhizomes under the mud surface that can grow the plant further out.
Close up of Spartina flowers.
Controlled in the Kaipara Harbour, any sightings of Spartina outside this area must be reported to Auckland Council. Care must be taken when controlling this plant that rhizomes are not left in the mud.
Spartina growing in the muddy ground by the water.
Some types of Spartina in NZ can set viable seed that is distributed by tides. Forms dense mats preventing other coastal native plants from establishing.
Photo credit: Weedbusters