The weed I want to wipe out

09 May 2012 People are passionate about different things. For some it’s their football team, for others it’s a favourite singer or actor. However, for some members of the KI NRM Board it’s the eradication of weeds and they have particular targets in their sights!

Board member Kathie Stove would choose to wipe out the South African daisy known as white (or silver) arctotis (scientific name Arctotisstoechadifolia).

“This daisy is one of many garden escapees starting to take over coastal environments on Kangaroo Island. It is an attractive ground cover with its silvery foliage and showy white daisy blooms and I can understand why people would want to grow it. But pretty and dangerous can often go together and white arctotis is now covering sand dunes at Hog Bay, American Beach, and probably other places on the Island as well.

Many might see the carpet of white arctotis along the dunes as attractive but we need to look past superficial appearances to the threat that these weeds pose.

Unfortunately, it is still promoted as a garden plant that is useful for stabilising sand. It certainly does that but then forms dense mats that smother native dune vegetation and eliminate indigenous plants through shading and competition for resources.

White arctotis can also alter the dune structure and cause dunes to develop a steeper slope. We can see that effect at Hog Bay where its impact on the dunes means the steps to the beach need constant fixing. This might be avoided if we got rid of the arctotis and put back the gorgeous native grass Spinifex hirsutus which also has silvery leaves and interesting flower and fruiting heads.

Perversely, white arctotisis becoming less common in its native range along the western coast of South Africa, while it is taking over here and in other places with similar climates, such as California.

In the Henley South and West Beach Dune Reserve in Adelaide, white arctotis has become a priority weed. Other areas along Adelaide’s coast and in Victoria, Tasmania, Western Australia and NSW are starting to see the devastating effects of white arctotis.

And if we don’t do something soon, we’ll be in the same boat – and it will cost us a lot more money and effort to fix. Let’s get rid of it now.” says Ms Stove.


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