It is my mission in life to eradicate as much of these pests as possible. My December holidays especially are entirely spent on invader plant eradication, for it is the time for the notorious Pompom weed to proliferate and Lantana grows as if it is the last thing on Earth that is happening. I don’t do it for myself – it is my ‘Thank you’ to God for giving us such a beautiful piece of land to manage for Him.
If only we could have stayed in a perfect world – where every organism grows where God intended it to grow, and where all neighbours eradicate those that doesn’t!
My main concern at this stage is Lantana camara and Pompom weed (Campuloclinium macrocephalum). Many, many hours of my time go into the eradication of these two pests. The Lantana has thorns and forms thickets where nothing else grows, and the Pompom weed spreads by the wind and vegetative by its rootstock.The method of eradication for Lantana is cutting and spraying with herbicide. The Pompom flower heads must be taken off, dried in a bag and then burnt. Each bract in the flower head has about a hundred seeds! The plant is sprayed with an herbicide after the flower head was removed. This is labour intensive and the herbicide is expensive.
Lately Passiflora subpeltata (Granadina) has also start to become a problem and I have picked bags full of the fruit to burn this season. The plant has a very shallow root system and I pull it out completely and the pull the creeper plant from the trees. They luckily don’t have suckers that attach to the trees and are easily pulled down.
But – when I look at my plant list, and look at the hundreds of pictures of insects, then it is worth the while. Without a variety of plants, there also won’t be a variety of insects and other organisms. Every species is part of one or more food chains in an ecosystem.
We do have other Category 1 invader plants, but at this stage they are not a big problem and I am managing them to prevent large scale infestation. I spray them with the herbicide while I am busy with the bigger pests.
A plant that I think is underestimated so far, is the Mexican Ageratum, Ageratum houstonianum. I see more and more of them each year and they look very innocent… more reason to be concerned!
SANRAL upgraded the R40 road bordering the farm between 2007-2009, and they bought sand from us. Since then a number of new invaders has established themselves on the banks of the quarry. I think the seeds were clinging to their bulldozers and other soil moving equipment.
Category 1 – Declared weed, prohibited and must be controlled
|Family||Species||Common name (Mainly Afrikaans)|
|Asteraceae||Ageratum houstonianum*||Mexican ageratum|
|Asteraceae||Chromolaena odorata||Paraffienbos, Triffid weed|
|Asteraceae||Tithonia diversifolia*||Meksikaanse sonneblom|
|Asteraceae||Tithonia rotundifolia*||Rooi sonneblom|
|Asteraceae||Xanthium strumarium*||Kankerroos, Large cocklebur|
|Bignoniaceae||Macfadyena unguis-cati*||Cat’s Claw Creeper|
|Papaveraceae||Argemone ochroleuca ochroleuca*||Bloudissel/Mexican poppy|
|Solanaceae||Solanum mauritianum*||Luisboom, Bugweed|
|Solanaceae||Solanum seafortianum*||Aartappelranker, Potato creeper|
|Solanaceae||Solanum sisymbrifolium*||Doringbitterappel, Wild tomato|
Category 2 – Declared invader (commercial and utility plants), allowed in demarcated areas by permit holders
Category 3 – Declared invader (ornamentals), no new planting, trade or propagation is permitted