Invasive Vegetation within the Mount Moreland Conservancy
One very positive thing that we can do is to remove all of
the invasive plant species that we have in our gardens. The reality is many of these plants have
already become invasive resulting in huge financial consequences for the nation not to mention the damage to
the natural environment. In these times of climate change there are going to be many other plants that could
also become an environmental threat so the safest thing to do is to progressively remove all foreign plants
from our gardens and replace them with local
plants that have adapted specifically for this place on earth.
The most invasive trees and
plants that are in Mount Moreland are:
- Singapore Daisy
Furcraea foetida Mauritius Hemp
Triffid weed - Paraffin
There are two ways to eradicate unwanted alien trees the most obvious is to simply cut the tree down, this
often has the disadvantage that if the stump is not treated with a herbicide immediately after cutting numerous new
trees will sprout up out of the soil from the roots which
are then very difficult to deal with. This is very much the case with Syringa and to a lesser degree Brazilian
Pepper. The other method is to poison the unwanted trees with a suitable herbicide such as Garlon with
the active ingredient triclopyr and or Tordon with the active ingredient picloram.
A few points to ponder before one rushes out and removes or poisons trees on their properties.
If there are a large number of or only invasive species trees on your property do not go out and remove
or poison the whole lot in one go this will denude the property which would have a negative environmental impact.
Instead work on a 3-5 year program to systematically remove the unwanted trees and to replace them with suitable
local trees such as those which I have identified as being suitable for Mount Moreland.
If you are going to poison a tree make sure that when it eventually rots and falls that it will do no
damage to life or property.
Do not plant trees from other regions in South Africa such as the Fever tree or Ficus bubu these are just as
much alien to this environment as a tree coming from South America
The most effective herbicide to use for the most commonly
encountered trees here in Mount Moreland the Brazilian Pepper
and Syringa are very easily poisoned with a mixture of Garlon with the active
ingredient triclopyr mixed with diesel oil at the concentration of 1.5% Garlon.
This mix is then simply painted in a band of about 250 mm around the entire trunk as close to the ground as
possible. The more difficult one such as Litsea may need the addition of Tordon to the mixture to be effective.
There are however a few trees that are close to impossible to kill using acceptable herbicides these trees need to
be cut down and the stump removed such as the Umbrella tree. These herbicides recommended when applied correctly
have very little negative impact on the environment and when compared with the negative impact of the tree that has
been poisoned this is negligible.
When planting trees in Mount Moreland due to the nature of
the soil it is far better to plant far less trees and do so properly so that the tree has a chance of growing into
a healthy specimen. My recommendation is for any tree regardless of the size of bag that it is in to dig a hole one
meter cubed then back fill it with one third well rotted compost and approx 100grams of fertiliser which has first
been well mixed. Plant the tree and water it well keeping the tree constantly moist until it has established
thereafter it will need to be watered from time to time for the first year or so during times of
By Michael Hickman
What is the difference between a weed, an invasive alien plant, a bush
encroacher and an exotic plant?
Is a general term
used to describe any plant growing where people do not want it to grow. Examples of these would be plants
growing up through paving or growing between crops, competing for water and nutrients.
An invasive alien plant:
is any plant which does not occur naturally within a region,
and which has rapidly colonised land or water, often displacing naturally occurring vegetation. Such plants enter a
region, either by being imported for horticultural or economic reasons or the seeds and spores have entered a
region accidentally in animal feed, by the wind or stuck to peoples clothing.
A bush encroacher:
is a woody species (usually indigenous), which has started to
colonize a grass-domained ecosystem.
are plants imported from another region where they do not occur naturally. Unlike invasives, these exotic
plants do not have a habit of spreading outside of areas where they have been purposefully planted.
Why are invasive plants
* They spread rapidly, displacing naturally occurring flora and fauna thus reducing species
* The, bark, stems and foliage of many invasive alien plant species do not properly break down as they would in
their home region, eg Pine needles. This has a leaching effect on the soil as nutrients removed from the soil by
the alien plant are not returned by normal decomposition.
* Soil PH can be altered by some species of invasive alien plants, e.g. Gum trees, making rehabilitation after
removal of invasive alien plants more difficult.
* Many invasive alien tree species take up much more ground water than indigenous species.
* They increase the severity of fires as they increase the fuel load resulting in ‘hot’ burns.
* Invasive alien plants are not as effective at binding the soil on river and stream banks and reduce the velocity
of water flow during peak flow periods. They can thus be a contributing factor to damage caused by flooding.
Do I have a legal obligation to keep my land free of invasive alien
Yes, you do.
In terms of the Conservation Act 1983, Regulation 15 ( applicable to ALL LAND regardless wether it is zoned
agriculture or not) and the National Environmental Management Act of 2004, ALL LAND owners have a legal obligation
to keep their land free of invasive plant species.
What are the benefits of eradicating invasive alien plant infestations on my
* An increase in property values
* Better visibility on one’s property as alien vegetation often hides illegal dumping.
* The return of wildlife such as birds, butterflies and other creatures.
* An increase in plant diversity.
* Better soil binding ability which reduces soil erosion
* More efficient nutrient recycling due to better decomposition of leaf litter
* More stable soil PH.