Plants of the arid outback
Set in the desert outside Port Augusta, the Australian Arid Lands Botanic Garden highlights the stark beauty and remarkable survival of the country’s toughest plants
You’re in another world when you visit Port Augusta, about a three-hour drive north of Adelaide, surrounded by the rugged beauty of arid Australia.
An area is classified as arid when it receives less than 250mm of rainfall per year, and this applies to more than two-thirds of Australia. There are arid regions in every state and territory, except Tasmania.
Located at the top of Spencer Gulf, Port Augusta is a natural landscape of extremes ranging from desert to mangroves. This small coastal city has been described as the crossroads to Australia because it is often a drive-through for people heading north to Alice Springs and Darwin, or west to Perth. Yet Port Augusta itself is worth a visit, if only to see the home of my favourite botanic garden.
Opened in 1996, the 250ha Australian Arid Lands Botanic Garden represents arid outback Australia – harsh and rugged, yet spectacularly beautiful.
Set in a desert, it has no lush lawns or large, shady, exotic trees, but gives a true representation of the southern arid zone of desert Australia.
This is the only botanic garden where you could stand at the Matthew Flinders Red Cliff Lookout, looking towards the Flinders Ranges in the far distance, and at the waters of Spencer Gulf below, and see a dolphin swimming while a goanna scuttles past your feet. Everywhere you look, the views are breathtaking. If your yen is for lush green, please enter this garden with an open heart, as those kinds of plants are not sustainable in this harsh environment.
Many of the plants growing here are becoming rare in the wild because of land cultivation, low rainfall across the southern states, and extreme weather conditions, as well as pressure from
grazing animals also affected by drought, including kangaroos. Temperatures range from a couple of degrees below zero, with possible frost, to the high 40s, and the winds can be extreme. This shows just how tough desert plants really are.
The garden is broadly divided into collections of plants from different arid regions of Australia, including the Gawler Ranges, the Flinders Ranges, the Great Victoria Desert and the west-coast Mallee. While these collections are located fairly close to the Visitor Centre, vast areas of the site remain as local native chenopod shrublands composed of low saltbush, bluebush and other hidden treasures.
Apart from all the amazing plants, you’ll also find interesting sculptures scattered throughout the garden from an exhibition held every second spring, and some great walking trails.
Here are some of the highlights and features to look for when visiting the Australian Arid Lands Botanic Garden.
the courtyard area
From the car park, the entrance to the garden is along a pathway lined with dense plantings. This leads you into a courtyard framed by a rammed-earth wall. A window in the wall creates a spectacular image at any time of day.
In the courtyard are massed displays of native annuals blooming among other, more permanent plantings. Sturt’s desert pea (Swainsona formosa) and paper daisy (Rhodanthe chlorocephala subsp. rosea) are a picture in flower, but even when these are past their best, there’s always something else flowering in the garden, despite the harsh desert conditions.
Rabbits and roos have been causing problems here recently, requiring the installation of low fencing to protect the display of annuals. This is a symptom of the drought, and measures are being taken to fence the entire property to manage the nibbling wildlife.
Wander through the courtyard to the Visitor Centre, a rammed-earth building that fits comfortably with the surrounding landscape. Here you’ll find the gift shop, the nursery and the Bluebush Café, where you can enjoy great coffee and lovely food, including their signature Quandong Cake and Arid Tasting Plate.
wildlife
The garden is home to a variety of native animals such as goannas, lizards, snakes and various mammals. It also has a large number of birds, with a recent bird survey recording 150 species. While birdlife can be spotted all over the garden, there are also two bird hides available for those who want to patiently wait to spot their favourite birds.
historic plant species
When Scottish botanist Robert Brown visited the area in 1802 on his expedition with English navigator Matthew Flinders, he collected many arid plant species that were new to the horticultural world – nothing like them had ever been seen or collected before. The species featured in the garden around the car park at the Matthew Flinders Red Cliff Lookout were collected from Mount Brown, which is visible from the garden.
signature tree
Western myall (Acacia papyrocarpa) is the signature tree of the Australian Arid Lands Botanic Garden – and its official emblem. While many acacias are quite short-lived, western myall trees reportedly live for up to 1000 years, and it’s believed that some in the garden may be 600 years old. They are very slow-growing, with a beautiful grained wood, and silver-blue foliage that shimmers in the breeze. The specimens in the garden are 8–10m high.
In the height of summer, it’s amazing how cool it feels sitting in the shade of one of these trees. The trunks are very gnarled and distorted, and some of the older trees have large branches growing from the main trunk that rest on the ground. In some of the sandy blowout
areas in the garden, which have been affected by wind erosion, the woody root system of these majestic trees is visible, giving an insight into how the roots travel long distances in their quest for moisture.
These acacias germinate only after a large, flooding downpour of rain, which occurs in arid regions about four times per century. And with the advent of rabbits and grazing stock in the arid environment, it’s rare for the seedlings to survive and reach maturity.
emu bush collection
The garden has one of the country’s largest collections of emu bush (Eremophila spp.) growing in a botanic garden environment. In the Eremophila Garden, there are about 900 plants representing many of the 200 named species in the genus, with the different varieties providing colour for several months of the year.
You can see the wide variety of flower colours, leaf shapes and variations, as well as the plant’s diverse forms, from groundcovers and shrubs to small trees. Take note of the different flower shapes, too. Eremophilas that are pollinated by insects have larger, flatter, more open flowers, with special markings to allow the insect access to the nectar, while others have evolved with thin, tubular flowers that are pollinated by birds.
waterwise garden ideas
Within the botanic garden, the AridSmart Display Gardens feature six different courtyard-style gardens of uniform size (12m x 11m) that showcase the contemporary use of desert plants, and design principles that can be readily translated to suit any suburban backyard. You can download the concept plans and planting keys for these award-winning designs from the Australian Arid Lands Botanic Garden website (see box, right). Propagated AridSmart plants are available to buy at the Visitor Centre.
dedicated volunteers
It may seem odd for me to describe
The Friends of the Australian Arid Lands Botanic Garden as a feature of the garden, but this group certainly is! These volunteers help with all sorts of hands-on activities, from propagation of the AridSmart range of plants that are sold in the Visitor Centre, to vital maintenance jobs such as fencing. They also run guided tours of the site, starting at 10am, from Monday to Friday (except public holidays). Make sure you take a tour, as their knowledge is amazing, their enthusiasm is infectious, and they are so proud of this garden treasure.
protective measures
Signage throughout the Australian Arid Lands Botanic Garden directs visitors to stay on the paths, especially around the sand dunes. This is not only to protect native vegetation and young plantings, and ensure the bush homes of wildlife remain undisturbed, but also to protect the integrity of the exposed sand crust, which is brimming with microorganisms and fungi. The simple act of walking off the path can break their hold on the sand crust and cause erosion.
Staff and volunteers at the garden are committed to practising and promoting environmental sustainability. They do this by educating visitors and leading by example, and they’re doing a great job of both. The future of desert plants is in good hands with places like this helping to protect them. They are putting resources into conservation and research to ensure these species will always be available.