The team at Genus gets asked this question often.
While most people have an understanding of what is an exotic plant and what is a native plant, it is the definition of what is indigenous that causes confusion. Much of the work we do is governed by guidelines of local councils and there is a real focus towards protecting and conserving local ecologies and plant communities. So when council asks for a landscape design to use 100% indigenous plants, it may surprise a client who wants to plant their favourite Bottlebrush but is not allowed to!
So here is the Genus Landscape Architects definition of what are Exotic, Native and Indigenous plants.
This includes the wondrous array of country garden plants that were imported during and since European colonisation of Australia such as: Quercus robur (English Oak), Betula pendula (Silver Birch), Lavandula sp. (Lavender), Rosa sp. (Rose) and Buxus sp. (Box Hedge). The broad range of exotics also includes arid plants from the Americas (Yucca sp.) and ornamentals from Asia such as Acer palmatum (Japanese Maple).
This large and varied range of plants have only in common the simple geography of their origin (ie. not from Australia).
Well known natives include Eucalyptus sp. (Gum Trees), Callistemon sp. (Bottlebrush) and Melaleuca sp. (Paperbark). Just like exotic plants, this classification is purely geographical (and according to a modern-day border) so the range of different Australian native plant species spans from tropical rainforest, deserts, mountain woodland and coastal marshes.
Indigenous Plant Species
So what then is an indigenous plant?
An indigenous plant is a species that originates naturally from a specific area. Once again this classification is based on a geographical area, however it is more localised. Based on that you can have plants that are indigenous to Victoria, to the City of Frankston, or to a stretch of coastline between the beach and Kananook Creek.
It is important to recognise that a plant that is indigenous to a broader area (such as Victoria or Frankston) may not necessarily be indigenous to a more specific location within that area. Some plants may even become invasive and weedy once outside their specific origin. An example of this is Coast Wattle (Acacia longifolia) which is indigenous to Frankston but is considered a weed if planted away from coastal locations. The discussion on weed species gets quite involved and will be saved for a future post.
Why use Indigenous plants?
The Genus team encourages the use of indigenous plant species in landscapes, where possible. While their use helps to retain the unique natural ecologies of an area, they are also often a more practical and low maintenance option. Indigenous plants have evolved to suit local climate and soil conditions and once established they should require less watering than exotics or other unsuitable natives.
So next time you are presented with the question, what is the difference? – You can answer “It depends on where you are!”
Read more on natives vs exotics here at the Landscape Architects Network – The Native Debate.