It is a legal requirement in terms of the national environmental laws, local fire regulations and selling a plot, to clear alien species from plots. However, in the past the non application of laws and regulations has led to the continuous invasion of alien species. This has led to the continuous invasion of alien species, in all areas. Plot clearing of alien species is a necessity for many reasons.

However, this is an easily solvable problem by applying the correct techniques, the data gathered is in an update on data. The application of the wrong techniques solves the problem in the short term, however it makes the problem worse in the long term. In addition, this costs the plot owner a lot more money. Michael Austin has repeatedly demonstrated this in the Ward 8 area of the Overstrand/Fisherhaven & Hawston.

An example of alien species clearing

Shown below is an alien clearing example with the costs involved.

Vigorous Port Jackson regrowth with multiple stems from stumps, outcompeting Fynbos
Trimmed Australian Myrtle trees, with many Myrtle seedlings regrowth of Port Jackson from stumps and seedlings

The vigorous growth of Port Jackson on this plot was from the regrowth of stumps. This was because the stumps had been been slashed and not poisoned. Therefore, this results in quick regrowth with multiple stems from a large existing root systems. Previous clearing, had trimmed the Australian Myrtle into tree shapes, exposing the ground below. This resulted in hundreds of small seedlings growing around the now exposed base of the plants.

The clearing of the plot cost R2 500-00 for the first time. This involved cutting and poisoning all large plants and uprooting all seedlings. The date of the first clearing was 6 March 2020.

Second clearing of the plot

Second clearing of alien species with a 76% reduction in costs by using the right techniques
After good rains, a few Port Jackson seedlings and many Myrtle seedlings
Second clearing of alien species with a 76% reduction in costs by using the right clearing techniques
Second clearing scattered Port Jacksons seedlings with patches of Myrtle seedlings

After good rains, the plot had good growth of indigenous vegetation, no regrowth of stumps and scattered seedlings of mostly Myrtle and a few Port Jacksons. However, where the Myrtle trees had been cut down, there was dense growth of seedlings, in the bare patches. In addition, there were some indigenous seedlings emerging and the existing plants were growing much better and flowering.

The costs of the second clearing were R600-00, done in September 2020. This amounts to a 76% reduction in costs. In addition, the stronger growth in the indigenous vegetation resulted in a bonus. This is because the indigenous vegetation outcompetes the large alien species seedbank. A year later in April 2021, after good rains, there were only a few Port Jackson seedlings and still a number of Myrtle seedlings. These were easy to pull out by hand, achieving good alien species plot clearing.

Other cost information

There are many factors which affect the costs of follow-up clearing. Primarily, this is expressed in the regrowth of seedlings and the cost decreases can range from 60 – 95%. The mowing of plots has more effect on reducing the indigenous vegetation, however, it increases the number of Port Jackson stems which makes the problem worse. The result leads to a general increase in costs of clearing ranging from 20 – 50%. The detail can be found on this website in the category ‘History Bot Estuary matters’ and Botfriends Facebook page contains additional measured data. For more information on good eco-assessment and planning management go to the eco-assessment page or eco blog page, which contains all posts on the clearing of private plots and public spaces. For a complete list of blog posts go to the Home page, Category section with its appropriate sub-categories.


Displayed below is a recommendation from a satisfied client.

© 2019-2023 Greenheart Projects. All rights reserved.