What native plants should we cultivate? -  John Stephens

Are we doing the correct thing by growing Native plants other than those endemic to our own area?

Three or four years ago I noticed a very pretty creeper growing out of my pile of bricks collected after the construction of the house. This self-sown plant was thriving in an area where other plants barely survived, so I left it alone, meaning to follow up with some research into what it was. I should have known the identity of the plant as we had grown it in our previous garden. It was successfully used to cover portion of a side fence and trellis. I had a suspicion of what it was although I recently asked Col for confirmation. Yes, you have probably guessed, it was Sollya heterophylla, a West Australian causing problems in our south eastern region. Needless to say the offender has been destroyed, hopefully before any seeds were dispersed into the area. Our previous plant had been purchased not so many years ago from a local nursery! I don’t mean to upset our commercial friends, however should they have even had it in stock?

This incident made me a little more aware of the dangers of "introduced" plants. How many times have you seen lawn clippings and prunings thrown over a rear fence on the edges of suburbia? This is only one example of our thoughtless gardening activities that assist feral plants to spread. Of course our animals and birds are responsible for an arguably greater impact through seed dispersal from existing plants, not to mention wind.

It was not long after this that my eldest son said "Dad I’ve purchased a book that may interest you". It was "Feral Future" by Tim Low. After having read this and Tim’s subsequent title "The New Nature" I now view our native plants in a different light as he describes in detail much of the past and impending change to our environment.

It is well documented that plants introduced into another country can thrive and cause extensive problems. We see this with "weeds" introduced into our own country such as blackberry, boxthorn, Paterson’s curse, asparagus fern, pine, ragwort and cotoneaster, just to name a few with which I am familiar. There are many countries where our native species are going "mad". A quick search of the Internet will reveal the concerns held in regard to expanses of Melaleuca quinquenervia in Florida Everglades, only introduced into the area in the early 1990’s and now covering thousands of acres and considered a noxious weed in many U.S. states. Also West Australian Acacia saligna, introduced into South Africa for its tan-bark is now growing profusely around Cape Town. Both locations are attempting biological control – fingers crossed! However some of these feral plants can be quite a surprise. For instance can you even imagine any of our lovely ferns running rampant? Ferns don’t run very fast, shouldn’t take much effort to catch and eradicate them, should it? Well Cyanthea cooperii from Australia is doing just that in Hawaii, with thousands of them up to four metres tall discovered invading Haleakala National Park.

We live in a huge continent with such a diverse range of habitats that the range of species in a location can be akin to being from another country. This is particularly so of species from Western Australia, having been effectively separated from the eastern states by a dry terrain for thousands of years. Therefore introducing a plant from one part of the country into another can be fraught with menace if the plant is well suited to conditions in the new area.

Many of our native Australian plants when grown out of their "normal" area can quickly spread to surrounding properties. This is particularly so when your property borders bushland. You no doubt have heard of the problems with Acacia baileyana, a plant which originally only grew in an area approximately twenty-five kilometres square near Cootamundra in New South Wales. It is an attractive plant and has been spread far and wide by gardeners and the nursery trade. Little did we realize that it would become the problem it is now, listed as an errant plant around Sydney, Melbourne, Canberra, Hobart, Adelaide and of course other provincial locations. What about our own Gippsland Grevillea rosmarinifolia? This bird attracting plant found its way into many gardens, particularly in schools where its prickles were perfect for keeping kids off the garden beds. It is probably responsible for much of my interest in native plants. I have many lovely photographs of this plant as a result of the targeted Eastern Spinebill having departed before I had a chance to release the shutter! Australian plants listed in our own "Common Weeds of Gippsland" are Sollya heterophyla, Paraserianthos lophantha, Acacia baileyana and Pittosporum undulatum. With possible changes in climate, the introduction of new animal species and other influences it is even possible that some new "nasty" plants may be already residing in our gardens.

According to Tim Low, Victoria is the worst affected state with around two hundred Australian plants on the weed list and thirty percent of the Parks Victoria budget spent on controlling native plants on the Mornington Peninsula. This is arguably the worst area in the state with many native plants, grown in gardens and an arboretum in the 50s onwards, now gone wild. The speed at which the "plant invaders" have encroached on our bushland is frightening, aided in the main by the activities of us humans. Call me a pessimist; however I believe that inevitably many of the species we now know will succumb and we will be left with a much poorer range of species. What can we do to help? Shouldn’t we be doing our utmost as native plant supporters to at least slow this invasion by being aware of those plants which have a nasty streak and refusing to purchase these plants even if stocked and promoted?

We have a real responsibility to ensure that the plants we grow do not become "feral", that we are not responsible for speeding-up a process of change which looks alarmingly like a forgone conclusion. We need to choose our plants wisely, be alert to any changes in our surrounding bushland and inform others of plants or activities that are likely to cause a problem.

References and recommended reading –
Low, T. (1999), Feral Future: The untold Story of Australia’s Exotic Invaders, Penguin, Melbourne
Low, T. (2001), The New Nature: Winners and Losers in Wild Australia, Viking, Melbourne