Giant reed

Arundo donax

Giant reed

Giant reed

Legal Status: Unwanted Organism - BNZ
Status in New Zealand: Established
Organism: Land plants

Other Common name: Arundo Grass


Giant reed is a clump-forming bamboo-like grass with a dense root mass and short rhizomes. It can grow up to 5 m in height. Hollow stems, up to 4 cm across, are initially erect but become semi-lax over time. Bluish-white (occasionally white-striped) bamboo-like leaves (30-90 x 5 cm) with parallel veins are arranged alternately, clasping the stems. A plume-like flowerhead is produced at the top of the stem in late summer.


This grass forms tall dense clumps, usually on wasteland, but is a potential weed of river and stream margins that can block waterways, promoting flooding. It provides a habitat for rats and possums, and poses a fire risk.

What to do

Contact your regional council to determine the status of this species and responsibility for control and/or advice on control.

Page last updated: 20 March 2009