Saturday, 19 August 2017

Alien Invasive Giant Reed, Spanish Reed Arundo donax

Spanish Reed, Giant Reed Arundo donax, giant cane, is one of the invasive alien plants that we have been eradicating at Mount Moreland and other sites in the area. Spanish Reed Arundo donax is a tall perennial cane which is mostly found growing in damp soils.  Spanish Reed Arundo donax is one of several species of grass called reeds. Spanish Reed Arundo donax is not to be confused with our local reed Phragmites australis known as uMhlanga in Zulu.

Spanish Reed Arundo donax

Spanish Reed Arundo donax is native to the Mediterranean Basin and Middle East, Asia, and probably also parts of Africa and the southern Arabian Peninsula. Spanish Reed Arundo donax has been widely planted and has naturalized in most of the mild temperate, subtropical and tropical regions of both hemispheres of the world mostly in wetlands and riparian habitats.

Spanish Reed Arundo donax which is highly invasive generally grows up to 6 meters; under ideal conditions it can exceed 10 meters. Spanish Reed Arundo donax resembles a very large common reed Phragmites australis.

Spanish Reed Arundo donax that has been treated with our herbicide gel at Mount Moreland

As already said Spanish Reed Arundo donax is a highly invasive plant that is one the fastest-growing plants in the world growing up to 10 centimeters in a day;

In South Africa Spanish Reed Arundo donax has been given the Cat 1b invasive status.

Category 1b – Invasive species require compulsory control as part of an invasive species control programm. Due to their invasiveness, infestations may qualify to be placed under a government sponsored invasive species management program. No permits will be issued to keep them.

Another view of Spanish Reed Arundo donax that has been treated with our herbicide gel at Mount Moreland

In South Africa Spanish Reed Arundo donax was identified as one of those established invasive species that are most destructive. The need here is to run coherent control program and that gains are maintained. Giant Reed, Spanish Reed Arundo donax readily out-competes other vegetation, invades watercourses, road verges and moist sites away from water.

A search on the internet makes it very clear that Spanish Reed Arundo donax is difficult to control, this I have also established from my own experience. Herbicide application to mature plants is rather ineffective. Spanish Reed Arundo donax has dense growth and thick root masses which makes manual or mechanical removal difficult, this method does a lot of damage to the environment and is expensive to carry out. Deeply buried rhizome pieces re-sprout and soil-disturbance may be severe. Follow-up after manual removal is essential.

Spanish Reed Arundo donax that has been treated with our herbicide gel at Mount Moreland the result six months after treatment  

The application of herbicide is reasonably effective if one cuts back Spanish Reed Arundo donax and allowing re-growth to reach about one meter and then to spray with a glyphosate herbicide is the method most recommended. Regular follow-up over a period of about three years is required.


I together with Ecoman have developed a method of eradication that is far more effective where we cut down Spanish Reed Arundo donax then treat the re-growth with a herbicide gel that we have developed.

Inspecting Giant Reed Arundo donax that we treated with a new improved  herbicide gel last week, the results are promising

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