Weeds in our Area (Part Three)
By Bob and Ena McIntyre – Garden Route Branch.
Lantana camara is considered one of the 10 worst weeds in the world and comes in at number four in South Africa. Not only is Lantana very invasive and classified as a transformer but it is also one of the most common causes of livestock poisoning in South Africa. Cases of human poisoning have also occurred.
Lantana is easily identified by the multi-coloured flowers that may vary from pink, red, crimson, orange, yellow or white. The flower head is flat and compact often with multiple colours in a single flower head. The fruits turn black when ripe, birds love them and evidently the fruits are non-toxic to birds, rodents and monkeys. Both birds and animals are seed dispersers.
Control methods vary with much research having been invested in biological control agents. Regrettably success has been limited due to the fact that over 50 different variants of Lantana have been identified and effective agents have only been identified for a small number of the variants.
Conventional control involves chopping down dense bushes and treating the stumps and re-growth with a registered herbicide. Exercise caution during chopping not to leave behind any cuttings with nodes in contact with soil - these readily take root and establish new plants. “Chopper” is recommended as the herbicide suitable for stump treatment and re-growth can be sprayed with a 3% mix of “Roundup” or other glyphosate herbicide.
Identifying seedlings and young plants makes control by hand weeding easy. A very simple identification method is bruising a leaf to release the exceptionally and very distinctive unpleasant odour. Please wash your hands well after contact with this plant.
Line drawing with acknowledgement to “ALIEN WEEDS AND INVASIVE PLANTS” by Lesley Henderson. Copyright © 2001 Agricultural Research Council.