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Photo Credit: John D. Byrd, Mississippi State University, Bugwood.org -
Giant reed leaves. Photo Credit: David J. Moorhead, University of Georgia, Bugwood.org -
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Giant reed seedheads. Photo Credit: Rebekah D. Wallace, University of Georgia, Bugwood.org
Also known as: Spanish Reed, giant cane, giant reed grass, elephant grass
Giant reed is a thirsty plant! It uses three times as much water as native plants. It can clog culverts, destabilize riverbanks, and outcompete native shrubs and trees. This is not a species we want growing near our waterways!
Description:
| Life Cycle: | Perennial (life cycle lasts more than one year) |
| Early Detection and Rapid Response species: | Yes |
| Height: | Up to 20 feet (6 meters) |
| Leaf Description: | Blue-green leaves are flat and taper to a fine point. Each leaf can grow to over a foot long. The leaves grow off a bamboo-like stem or cane. |
| Fruit & Flower Description: | It does not produce flowers or seeds in North America. In other areas, it produces a dense cluster of purplish flowers. |
| Bloom Time: | March to September |
Habitat:
- Giant reed is commonly found in riparian areasAreas that are directly adjacent to flowing streams, creeks, or rivers., floodplains, irrigation ditches and along roadsides.
- It grows well in moist areas, especially thriving in sandy or well-drained soils commonly found in areas subjected to annual flooding.
Impact:
- Giant reed develops dense stands which displace native vegetation, diminish wildlife habitat, and increase the risk of flooding.
- Its canes are readily flammable which can increase the risk of wildfire to riparian areas.
- Large stands remove large amounts of water that could be used for irrigation, native plants, and wildlife
What you can do about it:
- If you think you’ve found giant reed anywhere in Oregon, please report it to the Oregon Invasive Species Hotline.
- Mechanical control, such as digging and pulling up, are not recommended in treating giant reed due to its very large and deep rhizomes.
Look-alikes:
Giant reed is often confused with common reed (Phragmites australis). Giant reed is much taller than common reed. It also has wider leaves, thicker stems, and large rhizomes than common reed.
It also resembles many bamboo species (Phyllostachys sp.). The best way to tell these plants apart is by examining how each leaf attaches to the stems. Giant reed’s leaves attach around the entire stem.
Noxious Weed Listing:
| State of Oregon: | Class B |
| State of Washington: | Monitor |
More Resources:
- University of California, Weed Research & Information Center: Giant reed