Giant reed

Giant reed is a sturdy, perennial, bamboo-like grass with a dense root mass and short rhizomes. It can grow between 5–8 metres in height.

Description

• Leaves are maize-like, sharp-edged, <60 × 5 cm and alternating.

• Stems are spreading, clumping and < 6 m tall.

• Flowers are large, fluffy, purplish turning to silver inflorescences.

• Seeds dispersed by wind. Vegetative spread from rhizomes, rhizome fragments and stem layering.

• Habitats include riparian and forest margins, wetlands, saltmarshes, gullies, dunes, roadsides.

What you need to know

Forms dense stands and displaces native vegetation. Alters river and stream margins by blocking water flow. Impedes drainage and exacerbates flooding in agricultural systems.

Management approach

Giant reed is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.

Control

Do not attempt to undertake control of giant reed yourself. Report any sightings to us.