Photographers: Forest and Kim Starr Affiliation: Starr Environmental Source: Bugwood.org Copyright: (CC BY 3.0)
The giant reed (Arundo donax) is a large invasive grass that can grow up to 20 feet in height with leaves 1-2 inches wide and 2 feet tall. The roots are fleshy, and form deep masses below the soil. The giant reed flowers from August to September.
The giant reed is able to out-compete native vegetation by absorbing available water sources and creating dams resulting from large matted root growth. Structures such as bridges, can also be damaged resulting from the strong root mats formed. If a piece of the giant reed travels downstream, it is able to grow and become established in a new location from cuttings alone. There is also a presented threat of fire with the aggressive growth and high flammability of the giant reed. Native wild life species, such as the endangered bird Least Bell's vireo, are affected by the reduction in preferred habitat due to the overwhelming growth rate of the giant reed when introduced to a new area.
Little is known regarding sexual reproduction of the giant reed, but the most common observed reproduction method involves rhizomes that take root and sprout rapidly thereafter. Seed viability, germination, and dormancy information is still be researched.
The giant reed was believed to have been introduced to the United States in the 1800's through California based on its many practical uses. Commonly, the giant reed is used in making woodwind instruments and unfortunately there isn't a native alternative. The giant reed can also be used in basket making, for fishing rods, medicine, livestock fodder, and to prevent soil erosion.
Habitat: Giant reeds can become established in a variety of habitats including conditions that may be deemed unfavorable by other native vegetation. However, the most common habitat for the giant reed is in moist sandy areas such as road side ditches.
U.S. Present: AR, AZ, CA, FL, GA, IL, KS, KY, LA, MD, MI, MO, MS, NC, NE, NM, NV, OK, SC, TN, TX, UT, VA, WA, WV
Texas: The giant reed is found in a large part of Texas, with the exception of the panhandle where it has not yet been reported. View map provided by: EDDMapS
Mechanical methods of extraction or regular mowing are not very effective in eradicating the giant reed due to its ability to re-grow from small root segments or cuttings. Chemical treatment using systematic herbicide such as a product containing glyphosate are proven effective methods of removal. Burning can be effective if combined with herbicide treatment following the flowering season ending in October. If using herbicides, it is important to take caution and not use a chemical that can effect native plants and water sources.
EDDMapS. 2012. Early Detection & Distribution Mapping System. The University of Georgia - Center for Invasive Species and Ecosystem Health.
Milius, Susan. 2002. Cryptic Invasion. Science News 161:8.
Perdue, R.E. 1958. Arundo donax - source of musical reeds and industrial cellulose. Economic Botany 12(4):368-404.
Robbins, W.W., M.K. Bellue and W.S. Ball. 1951. Weeds of California. Calif. Dept. of Agric., Sacramento. 55.
Tidwell, B. 1995. Native Habitat Restoration: Controlling Arundo donax. Monsanto Company.