For further information, please contact the Garden Advisory Service.
Sourcing the plants
Western Australia is fortunate in having several specialist nurseries and garden centres dedicated to Australian and, particularly, Western Australian plants.
Both common and unusual varieties from Western Australia are also grown by the volunteer group, Friends of Kings Park, and sold at their quarterly native plant sales. Consequently, availability is not a problem.
Please never dig up plants from natural habitats. This practice is illegal. It impoverishes the environment, and it can also be a means of introducing pests and diseases to your own garden. What you see growing in the bush may be the same species that you see at a specialist nursery, but often it will not be the same form.
Plant selectors have brought into cultivation many different forms with more horticultural appeal, such as dwarf, compact and prostrate forms of certain shrubs and trees. Plant breeders have also developed cultivars with showier flowers or extended flowering periods.
There are now plenty of superb Australian plants - and, in particular, Western Australian ones - to suit every style of garden, from cottage to classic formal to minimalist courtyard. The Backyard Botanicals Garden within Kings Park can help you choose species are right for your garden.
Although many Australian and particularly Western Australian plants have evolved in poor soils, they perform better if soil conditioner is used. It makes the difference between the look of bushland where plants are merely surviving and the look of a garden where plants are thriving.
Improving the soil does not mean changing its whole nature, however. If your soil is alkaline or acidic, it is best to accept the status quo and choose plants that prefer those conditions - which you already do when selecting exotics. Many garden centres will do a quick pH test if you take in a soil sample.
If you want to have some acid-loving species but your garden is alkaline, or vice versa, grow them in containers where you can easily create the right conditions. Use a fairly open potting mix for container cultivation. It is worth finding out the history of your block. For example, in a new subdivision that has been built where a market garden once stood, the soil may have high levels of phosphorus, which some Australian genera cannot tolerate - although plenty of others can.
Staff members of nurseries or garden centres that specialise in Australian plants will be able to recommend genera suitable for your soil, including those that tolerate phosphorus.
Planting and watering
Autumn to early spring is the ideal time to plant Australian species. Planting is possible outside this time frame, but extra care of the plantings would then be essential.
Choose young plants, check that they are not rootbound, and water them after planting. Dry area species should survive just on the winter rains and, once established, will not need supplementary watering. Many other Australian plants have low water requirements but, contrary to popular belief, not all Australian plants are drought-tolerant, so ask garden centre staff about watering requirements, particularly for the first year.
Today subsurface trickle irrigation is recommended because water is delivered straight to the root zone and is not lost through evaporation. Older gardens usually still have overhead sprinklers which are not ideal, as water gathering on foliage may create humid conditions that encourage fungal disease.
Contrary to popular belief, however, most Australian plants can tolerate a sprinkler system provided they are not over-watered. Over-watering reduces their flowering and produces lush growth that is more attractive to pests and diseases. In the case of species that hail from dry areas, over-watering can kill them.
While mulching is not absolutely essential for many Australian plants, it does help to reduce evaporation and keep the soil cooler. Mulch also has an aesthetic role in some people's opinion.
Avoid piling on more than 50 mm of mulch, keeping it away from the base of the plant, as excessive mulch can suffocate the soil and is bad for any plant. Always buy good quality mulch from a reputable source so that you can be sure it is not harbouring fungal diseases.
An Australian groundcover is a good, living alternative to conventional mulch if you are willing to be patient while it grows and spreads. Stones and well-placed rocks also act as mulch, and can be beneficial for dry area plants that prefer less humidity around them.
Australian plants need only a little fertiliser, and the slow release type is recommended. Over-fertilising is counterproductive because, just like over-watering, it produces lush growth that attracts pests and diseases.
Kangaroo paws are particularly susceptible if you over-feed them. For genera that cannot tolerate phosphorus, use a fertiliser that has been specially formulated to their needs. General fertilisers containing phosphate can be used on genera that are able to tolerate phosphorus, allowing you to grow them in combination with exotics.
Read the label to see whether it recommends a dosage suitable for 'native' plants, and always use a measuring cup rather than just throwing on by the handful.
Pests and diseases
An advantage of many Australian plants is that they have small leaves and flowers or large flowers consisting of a great many small parts, where pest and disease damage tends to be minimal in terms of visual impact.
Generally, people who grow Australian plants are interested in the environmental aspect and consequently do not want to use chemicals to control pests and diseases. Their reward is the fact that those same plants tend to attract birds and beneficial insects that keep the pests in check. To maintain this natural balance, you should have enough different plants to ensure there are flowers in all four seasons of the year.
Further information on managing pests and diseases is available from the Department of Agriculture and Food.
The main reason that the 1970s fashion for so-called native gardens ended in disillusion was the lack of pruning, resulting in shrubs getting not only too big but also badly out of shape. This happened because people had imagined Australian species would take care of themselves. It is a prime example of treating Australian plants differently - by contrast, nobody has ever assumed exotic shrubs could be so totally ignored.
The best way to create a neat, dense, compact shrub is to trim it early in its life. This may mean sacrificing the first year's flowers, but the reward will be a nicely shaped shrub covered in flowers the year after. Continue to prune annually after flowering. If you have mature Australian shrubs that have become straggly after some neglect, reshaping may be possible if the stems you want to prune still have foliage. But if the shrub has become too woody, so that the place where you want to prune each stem is devoid of leaves, it is unlikely to produce new shoots at those points.
Instead, as a last resort, try lopping it off at the base. Again, this harsh treatment parallels natural events - such as bushfire or grazing by animals - and many Australian plants automatically respond by shooting afresh from the base. By pruning lightly and regularly you can prolong the flowering period of certain plants, banksias being good examples. Nip out each flower once it is spent, as this produces a more compact habit and new flowers. It is exactly the same routine that you probably already practice on your roses.
Not only do some people think Australian plants can be neglected, they also expect them to live forever just because they have a reputation for hardiness. As with many exotics, certain Australian plants only perform well for a limited period of time.
Some shrubs and trees may have a fairly long life but some herbaceous perennials should be regarded as short-term items, to be replaced periodically. Red and green kangaroo paw (Anigozanthos manglesii), for example, is best treated as an annual. Hybrid kangaroo paws may last three or four years, after which their best performance is over. Lechenaultias also should be replaced after a year or two when they have lost their looks.
Be aware that over-watering and over-fertilising may shorten the life of Australian plants. They belong to an ancient flora that has never relied on outside help, and you can kill them with kindness by forcing them to grow at an unnatural rate, causing them to reach maturity - and old age - too soon.
Top ten tips
Choose or prepare your planting site so it is free of weeds, well drained and does not have high levels of phosphorous.
Install an efficient watering system such as trickle irrigation.
Choose the right plant to suit your garden conditions from an accredited nursery.
Plant from autumn to early spring for best results in areas that have winter rains.
Fertilise lightly with slow release fertiliser suitable for Australian Plants.
Mulch up to 50 mm deep while keeping the mulch away from the base of the plants.
Maintain the garden weed free to make space and nutrients available to plants.
Prune established plants after flowering.
Prune young plants regularly and lightly to develop good form.
Replace your plants when they start to decline.
- Last Updated: 21 February 2014