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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.
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) tall |
| 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: | Its flowers are large plumes that grow from the ends of its stems. In North America, flowers either don’t form seeds or form infertile seeds. |
| 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 and plenty of sun.
Impact:
- Giant reed develops dense stands which displace native vegetation, diminish wildlife habitat, and increase the risk of flooding.
- Its canes are highly flammable which increases the risk of wildfires.
- 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 is limited to younger, smaller patches due to mature stand’s extensive, tough underground rhizome network.
- In the spring when the canes are small and the ground is moist, plants can be removed with shovels and pickaxes.
- It is vital that all the root fragments are removed from the soil and all plant materials are disposed of in tied plastic bags in the trash – not yard debris or home compost.
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 species). 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:
Download the Giant Reed Best Management Practices Factsheet
- University of California, Weed Research & Information Center: Giant reed