S/Reed and Ginger s1

Weeds in our Area (Part Fifty One)

By Bob and Ena McIntyre – Garden Route Branch.

Arundo donax (Spanish reed)

With the Festive Season on our doorstep and in many minds already underway, we welcome all our visitors and the new “settlers” to our special place in the sun. With the influx of people we believe that revisiting some of our green enemies that were covered in the early days of this column would serve a useful purpose.

Arundo donax (Spanish reed, Giant reed, Spaans(e) riet), (Family: poaceae – grasses and reeds) have a significant presence in Wilderness in the shape of the variegated version, common along the stretch of road to the Fairy Knowe entrance. A gallant attempt to cut these back has resulted in an even greater proliferation – see below.

During the 80’s the Arundo donax ‘variegata’, originating from the Mediterranean region was enthusiastically promoted in gardening books as a striking evergreen reed for the large garden – interestingly it was also noted that cutting back older stems to ground level would encourage new growth. It was recommended for its foliage, for planting along streams and furrows and close to dripping taps – water was clearly not an issue twenty odd years ago. Another interesting note was that it was only suited to areas where the spread could be controlled.

Identification: The plant is easily recognised – it is a tall robust reed that reaches up to 6m in height. The long leaves of ‘variegata’ are streaked with a rich creamy white and the leaf tips are soft or firm but not spiky. Leaf sheaths remain on the stem for a long time. The inflorescences are cream or brown and appear throughout the year.

Invasive status: The Giant reed is a category one invader weed – translate as remove and destroy. It transforms moist areas where indigenous vegetation is out-competed and unlike our indigenous reeds also occurs in roadsides away from water. There is plenty of evidence of this at the above site.

Control: As with all reeds, this plant is difficult to control as it readily grows from rhizomes and even from a small piece left behind in the soil. Manual or mechanical means to remove the entire plant is recommended. Follow-up with hand-pulling of any re-growth before the plants get large. Large areas should be cut down to ground level, and the entire root system dug out. Please take care not to dump any on your compost heap as it will simply root re-grow on your compost heap instead. Ideally – shred the material before disposal or alternatively rhizomes can be left to dry out and then burnt.

Indigenous Substitutes: Phragmites australis (Common reed) and Typha capensis (Bulrush) or even better some of our stunning fynbos restios such as Ischyrolepsis subverticellata (Tuinriet), Thamnochortus insignis (Thatchreed, Albertinia dekriet) and Rhodocoma capensis.