Difference between terrestrial and aquatic plants

  • Aquatic plants are plants that have adapted to living in water related environments (saltwater or freshwater). They are also referred to as hydrophytes. These plants require special adaptations for living submerged in water, or at the water's surface.  Aquatic plants can only grow in water or in soil that is permanently saturated with water.
  • A terrestrial plant, on the other hand, is one that grows on or in or from the land

Aquatic invasive plants commonly found in Joburg

  • Red water fern (Azolla filiculoides)
  • Water hyacinth (Eichornia crassipes)
  • Parrot’s feather (Myriophyllum aquaticum)
  • Pickerel weed (Pontederia cordata)
  • Kariba weed (Salvinia molesta)
  • Yellow water lily (Nymphaea mexicana)

How to identify alien species in your garden

There is no step by step guide to learning the different types of alien invasive plants (or any other plant), it just takes time, patience and effort. Identifying plants is not easy.

  • By using a guide book. Get to know the different parts of a plant. Some books may have a plant key which is useful but sometimes difficult to use. The smell of the plant (crushed leaves) can also be a useful guide.
  • By asking around, starting with your neighbours or residents association. Inviting someone to your garden could open avenues. Or take a plant for identification to a botanic garden, university, garden centre, nursery or to your local council extension office; remember to take as many parts of the plant as you can –a flower, stem with leaves and seed, fruit.
  • By using the internet. There is a vast amount of information and photographs on the internet for different countries.
  • By attending a course on alien plans.

Steps on how to remove alien invasive species from your garden

  • Section 75 (1) of the National Environmental Management: Biodiversity Act, 2004 states that the “control and eradication of a listed invasive species must be carried by means of methods that are appropriate for the species concerned and the environment in which it occurs”. Section (2) states that any action taken must be done with caution and cause the least possible damage to the environment and to biodiversity. Section (3) states that control must also be directed at the offspring, propagating material (flowers, fruit, seed for example)) and any regrowth of the alien species concerned.
  • Alien invasive plants are controlled using three methods: physical/mechanical (hand pulling, cutting, heavy machinery), chemical (by using registered poisons/herbicides) and biological (by introducing the plants natural enemies). Using a combination of methods is often the most effective means of control.
  • The first step is to identify the target plant correctly. Then determine the best method considering life stage of the plant using literature, expertise and the internet.
  • Be certain you know what and how before you begin. Health and safety is paramount, have the correct functional tools and personal protective clothing and equipment. Beware of possible damage to infrastructure and the environment. Generally do not conduct alien invasive control when there is a wind blowing as this could cause a tree to topple in the wrong direction and could cause herbicide to drift. If you are using a herbicide, always follow the manufacturer’s instructions on the label.
  • Some invasive alien plants may contain a poisonous sap and some have nasty spines, prickles or hairs. Beware.

How to remove large alien invasive plant species e.g. Bluegum Tree

  •  If the tree is large, if the tree is close to infrastructure or if you are unsure of your capability, then it’s preferable to get an expert to remove the tree for you. The cut stump should then be treated with herbicide.
  • One person can do a lot toward successfully removing invasive species. If you have an invasive plant in your garden and it has the potential to become a large tree, rather remove the plant immediately. As time goes by, it becomes more difficult and costly to remove and the potential to damage infrastructure increases.

How to remove challenging plants eg. sprouting invaders (wattles)

  • Many alien plants, if they have not been cut or poisoned properly, will sprout again from the cut stump. Generally, once the new growth is about knee high, it can be sprayed with a suitable registered herbicide. Remember to check regularly if all regrowth has been killed and, if necessary, re-spray.
  • Also look for seedlings germinating around the cut stump. These can usually be pulled up by hand or dug up.