Giant Reed - Arundo donax

Arundo donax, is commonly known as Giant Reed or Spanish Cane.  Originating on the Indian subcontinent, its native range extends from the marshes of Eastern Europe to Indo-China and it is now found in most temperate and tropical climates throughout the world.  It has traditionally been selected as the plant of choice for manufacturing mouthpiece reeds for woodwind musical instruments like oboes, clarinets, and saxophones.

Extraordinary annual growth and high cellulose content make Arundo an ideal crop for converting solar energy to bio-fuels or industrial fiber.  Reeds exceed twenty feet in height and the dense growth of Arundo tends to exclude other vegetation.  These characteristics favor Arundo for commercial monoculture but also require its exclusion from habitats for less aggressive native plants. 

Commercial varieties of Arundo donax produced by Southern Sun BioSystem’s exclusive Liquid Lab™ process do not yield viable seed and can be contained by buffer zones separating cane fields from lakes or rivers.   Buffers prevent down-stream proliferation of Arundo from floating dormant stems.

Arundo donax has attracted attention due to multiple potentially benefits such as phytoremediation, biomass production and landscape beautification. New discoveries include root zone enzymes of Arundo that decompose toxic residues from pesticides, refrigerants, and industrial solvents.  Other dual use applications include Arundo fuel or fiber production on land that also requires remediation of mine slag runoff or odor reduction from swine effluent or poultry litter.

Arundo  grows best in well drained soils where abundant moisture is available.  It thrives in sandy alkaline soils but it is adaptable to most soil types from heavy clay to loose sand with pH between 5 and 8.7.

Arundo readily grows in temperate to tropical climates (zones 5 and higher) but biomass yield will depend on the length of the growing season and rainfall.  Annual precipitation can vary from 12 to 160 inches (3 to 40 dm).  Arundo survives both periodic flooding and severe drought.  In one study of side-by-side irrigation regimes, annual crop yields after four years without irrigation in a dry Mediterranean climate dropped below 8.5 dry U.S. tons per acre (19 t dm/ha/yr), where irrigating 1.73 inches/ year ( 44 mm/yr ) for the same climatic conditions produced 16.5 dry U.S. tons (37 t dm/ha/yr), and irrigating 33.82 inches/ year (859 mm/yr) increased crop yield to 20 dry U.S. tons per acre (44.8 t dm/ha/yr).  Annual production can potentially be increased to 45 US dry tons per acre (100 t dm/ha/yr) under optimal conditions of warm climate and underground irrigation.

Planting a 0.75 ounce (21 gram) slow release fertilizer tablet (20-10-5 of N-P-K) is recommended with the initial establishment of each new rhizome.  Additional surface broadcast of fertilizer (13-13-13) at a rate of 200 pounds per acre (224 kg/ha) is recommended prior to planting.  In years subsequent to initial planting, recommendations for annual fertilizer application vary from 200 pounds per acre (224 kg/ha) of 13-13-13 to 625 pounds per acre (700 kg/ha) of 15-15-15 plus 196 ponds per acre (220 kg/ha) of urea as top fertilizer.  While solid fertilizer needs to be applied after reeds have been removed by harvesting, liquid fertilizing through irrigation systems can be applied as needed. The optimum time for fertilization follows initial spring growth, which is driven more from stored energy in the roots than from photosynthesis and external plant nutrition.