One question I am frequently asked by visitors to the nursery at St Erth is “where are the native plants?” Many people believe that natives are somehow ‘better’ than exotic plants – more drought tolerant, tougher, easier to grow, lower maintenance, more environmentally friendly and with no risk of becoming a weed. But is this really true?
Australian native plants come from a wide range of habitats from deserts to rainforests, the tropics to the alpine zone. Many natives are adapted to arid conditions but some of the most spectacular are adapted to constant moisture and humidity. Waratahs come from coastal NSW, firewheel trees from Queensland rainforests and leatherwood trees from the wetter parts of Tasmania. Even though these plants are ‘natives’, they are not drought tolerant. They are completely unsuitable for those of us relying on washing-up and bath water for our gardens. But water is only part of the story. Sydney receives enough rainfall to grow Tasmanian leatherwoods but leatherwoods also demand cool summers. They cannot cope with Sydney’s heat. Many of WA’s exquisite wildflowers are drought tolerant but they have such specific preferences as to soil type, season of rainfall and presence of mycorrhizal fungi that they are almost impossible to grow outside their native range.
The belief that natives are by definition drought tolerant and indestructible is a complete myth. Unfortunately many nurseries cash in on this belief by stocking natives with large, eye-catching flowers, regardless of their garden-worthiness. How many of us have bought a stunning waratah or boronia plant on impulse, only to have it die six weeks later? I certainly have!
Another myth is that natives are the ultimate low-maintenance plants, needing no pruning or grooming whatsoever. It is true that natives will grow happily without much attention. But so will a rose bush or an apple tree. We wouldn’t stand for an unruly, thorny rose thicket in our gardens, yet we seem happy to let native shrubs grow sticky and rank. With proper pruning certain native shrubs can look great. Fiona Brockhoff and Jane Bourke’s gardens on Victoria’s Mornington Peninsula are created almost entirely using plants endemic to the peninsula, but they are kept crisply clipped and hedged so you can see exactly where the bush ends and the garden begins. The result is classy indeed. But these gardens aren’t only native gardens.
I have never understood why Australians are so convinced that native plants are somehow ‘better for the environment’ than exotics. Why do we feel guilty when we plant exotics and pious when we plant natives? Many people think that only native plants will attract native animals. Intuitively this sounds right, but my experience tells another story. The Garden of St Erth is surrounded by a state forest full of native plants. Yet our garden of exotic plants attracts plenty of native wildlife.
Wombats and kangaroos graze the lawns, wallabies munch on shoot tips and flower buds, honeyeaters drink salvia nectar, native bees collect sedum pollen, black cockatoos extract seeds from pine cones and gang gang cockatoos eat crabapples. Tree frogs inhabit clumps of Miscanthus grass and the Antechinus make their homes amongst our perennials. It seems our wildlife is far less neurotic about the origin of plants than we are!
Perhaps the most damaging myth in the natives vs exotics debate is that exotic plants are all weeds-in-waiting. This is simply not the case. There are thousands of exotic plants which have been grown in Australia for decades but rarely reproduce themselves outside gardens. When was the last time you saw a paddock blanketed with feral frangipanis? Yet some natives like the Cootamundra wattle (Acacia baileyana) and Native Daphne (Pittosporum undulatum) are vigorous self-seeders. They are officially listed as ‘weeds’ in some states, although how you tell the difference between a native plant extending its natural range and becoming a ‘weed’ is an arguable point (see Tim Sansom’s article on this topic in a previous issue).
Ideology aside, the fact of the matter is that not all native plants are garden-worthy and not all exotics are water-guzzling weeds. We sometimes forget that there are many areas of the world with climates as dry and tough as our own. If we choose non-invasive plants from these areas, and select the most dependable native plants, we will have a huge palette of colours, shapes and scents to work with in our gardens. At Diggers we don’t choose plants just because they are ‘native’ or ‘exotic’. We choose plants which are top garden performers so that you can create your own beautiful garden.
These photos show the dry garden at St Erth, created by gardener Chris Colligan. All of the plants in it come from other dry parts of the world such as the Mediterranean, South Africa, Mexico and the Canary Islands. These photos were taken in February – our hottest month – when many gardens look worn out. The plants in this garden have not received any additional water since they were planted out, just good soil preparation and plenty of mulch.
