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Let's all do our bit to eradicate ...
Crofton weed



In April when I attended my first EXCO meeting as Vice chairman I was handed the Crofton weed control portfolio. This was not exactly what I had been expecting. Something a little more glamorous perhaps. So it was with some trepidation that I accepted the challenge. And a challenge it turned out to be.


WHAT exactly is Crofton Weed?

It is a multi-stemmed, perennial herb growing up to 2m high with dark green serrated leaves. Small white flowers appear in terminal clusters about 5mm long from August to September.

Also known as Mexican Devil Weed this invasive alien has assumed serious weed status in Australia, New Zealand, China and India. Recently it has spread to Nepal where it has formed large thickets in the foothills of the Himalayas. Closer to home it has taken root in many kloofs in the Magaliesberg as well as in the Tzaneen area, KZN and the Western Cape. 


WHY? Having no natural enemies, Crofton Weed has spread to many north-facing kloofs in the Magaliesberg where there is an abundance of water and semi-shade. The seeds are distributed by wind born spores and by birds over vast distances to take root in any favourable area.

A voraciously thirsty plant, once firmly established forms dense thickets and is able to restrict and even stop the natural flow of streams and seepages. This means less water will flow to rivers. Dams will remain partly full, causing stress to all who rely on a steady flow of water.  


HOW? Prior to 2005 volunteers from the JHC. MCSA and other hiking clubs would meet annually, usually round about July at Castle Gorge car park for the annual Crofton Weed Blitz. Teams would be formed, the leaders would then proceed to areas of infestation and removal by mechanical methods would commence. Tackling areas of dense infestation proved to be very hard work indeed, subsequent follow-up inspections revelled that this method had little or no effect on heavily infested areas and that the weed just grew back again.

It was also pointed out by land owners in the castle Gorge Area that our efforts to eradicate the weed on their properties was viewed as trespassing and not appreciated despite all the good intensions


A NEW APPROACH. It was obvious that we were not making much progress because of the limited means at our disposal and the trespassing issue. A new approach had to be formulated that took into account the use of herbicides and the view points of all interested parties. Consequently contact was made with the following:



Several meetings were held at DWAF offices Heartbeespoort Dam and a joint venture consisting of all the parties was agreed upon as follows.

The Crofton Weed Blitz would take place on 10th July 2005 on JHC MCSA owned property and consist of:








FOLLOW-UP at Cascade Kloof in November 2005 showed that the treatment had been effective and that 95% of the weed was dead and rotting. Several areas were re-sprayed and other areas higher up were manually cleared. It was also noted that the indigenous plants had not been affected by the herbicide and were growing strongly.


CONCLUSION It is obvious that complete eradication of the weed impossible at this stage. The best control can be achieved is by manual removal in sparsely infested areas and by controlled use of approved herbicides in heavily infested areas. This must be carried out around June to early July before the seeds can germinate, subsequent follow-ups must follow.

Hikers are requested to monitor and report as a GPS way point, all infestations so that a comprehensive plan of action can be drawn up.






Robbie Macdonald