When is a botanic garden collection “indigenous”?

Mark Richardson, 2012

In a country where non-Australian garden plantings were the norm for more than 150 years after the first arrival of Europeans, it was a major change to propose only Australian plantings for a botanic garden. 

During the earlier times of that increased interest, it was common for the collections grown to be referred to as ‘natives’, and any garden growing Australian plants was called a ’native garden’ – and they often still are.

However, just because a plant collection comes from somewhere within the continent of Australia does not automatically mean it can be called ‘indigenous’.  One definition of the word ‘indigenous’ is “originating naturally in a region – not introduced” and this immediately raises the question of “How big is a region?”

For gardens such as the Australian National Botanic Garden in Canberra, the Australian Garden in Cranbourne and the recently renamed Australian Botanic Garden at Mt Annan, it is immediately evident they are displaying the flora of Australia.  However, for a garden representing a smaller region it is not as straightforward.

When the Alice Springs Desert Park was being developed in the 1990s it was very much seen as an ‘indigenous botanic garden’ and was planted to reflect the natural habitats of central Australia.  However, when we started collecting seed for the plantings and doing the planting lists for the habitats, the question arose – how far from Alice Springs should we represent?  Looking at something like the sand country habitat, there are areas of sand dunes that extend across a huge part of inner Australia.  By considering the flora within about 30 kms of Alice Springs it was felt we could draw a circle of 500km radius from Alice Springs.  And given the nature of central Australia that distance didn’t seem too far at all!  But even then, a lot of what we grew was not Alice Springs’ indigenous flora. 

Eurobodalla Regional Botanic Garden on the south coast of NSW refers to its display as showing the flora from within their “Collecting region”. This means that the plants grown in the Gardens are “principally from the Shire of Eurobodalla, but also includes parts of the Shoalhaven, Palerang and Bega Valley Shires”.  Even though the collecting region is much smaller than that of the Desert Park it still encompasses a wide “range of plant communities, from high altitude sub-alpine to coastal dune and sea strand”.

As such, both the Alice Springs Desert Park and the Eurobodalla Regional Botanic Garden (along with the ‘Australian’ gardens) could be considered to be collections of the indigenous flora in the regions they have chosen to represent.  However, a second question arising from the above definition is “When is a planting an introduction?”

While it is possible to make a region whatever size we wish, the issue of moving plants within that region still has to be considered.  Although most people are aware of the dangers that can arise from introducing plants from totally different continents, the term “native” or “indigenous” can give the impression that growing Australian plants is not the same.  The Cootamundra wattle (Acacia baileyana) is a good example of how that thinking has been proven wrong.  Growing naturally just 120km from Canberra in similar woodland, it has now become a significant weed in the ACT.  Likewise there are numerous Australian plant species that have displayed weediness when grown outside of there natural habitat, including, Melaleuca hypericifolia, Pittosporum undulatum and Billardiera heterophylla.

While the issue of weediness will not necessarily determine the region that a garden represents, it still means that it is important for a garden to appreciate that the area they have called their ‘region’ could still be a potential source of introduced weeds in the place the garden is located.

From the definition, it appears it would be necessary to grow what naturally occurs on the site of the garden to achieve a truly ‘indigenous garden’.  However, that does not necessarily mean only growing those plants and a good example is the new National Arboretum Canberra.  While it is primarily a mix of tree species from around Australia and the world, it includes one section which is dedicated to those tree species that are truly indigenous to the site.  Like the woodland habitat at the Desert Park and the coastal forest of the Eurobodalla Regional Botanic Garden it is providing an excellent opportunity to highlight the species that are truly local.