Nelson City Council

(Carex longebrachiata)

Boundary Control Pest

Australian Sedge is a perennial tussock-forming sedge, similar in appearance to both native and introduced sedges. However, the plant is distinguishable from other sedges by the way it shoots from within the bottom of the original stalk, its wing shaped leaves, angled flowering stems and catkin-like spikes. The plant normally flowers from October onwards and produces small, smooth, triangular nut-like seeds through to February.

Reasons for the Strategy

Australian Sedge is generally not palatable to stock, but it can form dense stands that invade pasture and reduce carrying capacity. The lateral spread of the plant is relatively small as the seeds fall close to the parent plant. However, care needs to be taken to avoid the risk of spread by animals. Once established, the plant is difficult to control.

Although Australian Sedge is assessed at “3” on the infestation curve, heavy infestations occur at Patarau. To prevent its spread, the occupiers of infested land are required to maintain a 20 m strip along their boundary with land that is clear or being cleared of Australian Sedge. Advice on machinery and stock movement to prevent the spread of the plant will also be provided. As these are the only known infestations in the South Island, the benefits of stopping this plant spreading far outweigh the costs.

Objectives

To control the spread of Australian Sedge from adjacent properties to land that is clear, or being cleared, of Australian Sedge.

Strategy Rules for Australian Sedge

1. The occupier shall destroy all adult and juvenile forms of Australian Sedge located 20 metres or less from the boundary of the land that he or she occupies where it adjoins land that is clear, or being cleared, of Australian Sedge.
2. The occupier shall take all reasonable precautions to avoid its spread on animals, machinery, and vehicles. A breach of Strategy Rule 6.1.5 is an offence under Section 154(r) of the Biosecurity Act 1993.

Biosecurity Act Requirement

No person shall knowingly sell, propagate, breed, release or commercially display Australian Sedge, under Sections 52 and 53 of the Act.