Background
Native to Eurasia, giant reed is a weed in waterways and wetlands, disturbed sites, and garden edges. Its aggressive habit allows it to displace native riparian vegetation. It can also be a fire hazard. It is sold as an ornamental and farmed for its canes.
Description
A perennial, creeping rhizomatous grass with hollow stems that grows 6-30 feet tall. The plant can regenerate easily from rhizome fragments. Rough-edged leaves grow up to 1-2 feet in length. Tightly packed cream to purplish-brown flowers form plumes that occur from early summer to early fall. Commonly mistaken for the related grass, phragmites, flower-bearing giant reed stems are hairless, whereas those of phragmites have silky hairs.
Control
Do not buy giant reed at nurseries. Mowing and tilling encourage new growth and should be avoided. Chemical control can be effective.