Harrisia Cactus (Harrisia martini) is another nasty cactus that was introduced into Australia from the United States as a garden plant. It has taken a strong hold in south-western Queensland, is now prevalent in the Yetmen – Boggabilla area and is gaining pace down the highway heading towards Moree. If you have ever pulled up along the highway around Goondiwindi, whichever direction you go you would not have to walk far before you would be pulled up by this nasty cactus spreading out in all directions.
A small infestation was recently discovered along the highway between Narrabri and Turrawan. The low-growing cactus is a Class 3 Noxious Weed which means that the plant must be fully and continuously suppressed and destroyed and the plant must not be sold, propagated or knowingly distributed. It can form large thickets blocking access to waterways, shade and can drastically reduce grazing capacity. Harrisia can be spread by seed as well as segments/runners from the plant. The fruit which is bright red (containing approx. 800 seeds) is very sweet and is attractive to birds, pigs, emus, goannas and ants! Each plant can produce in excess of 50 pieces of fruit so it has a potential to spread very rapidly.
Harrisia is not easy to control which makes it difficult to contain. Ideally if you only have a small infestation, the best advice is to pick off all the fruit, destroy by burning and then spray the rest of the plant. For any information on the identification or control of Harrisia, please contact Council’s Senior Weeds Officer, Clare Felton-Taylor on 0427 294 771.