Once in the not so distant past, as far as the eye could see, inland Australia glistened in the scorching midday sun with a sea of grey-green foliage; saltbush covered the land.

Old Man Saltbush stand between Hay and Balranald New South Wales.

Large herds of wild herbivores would move into a stand of saltbush and defoliate the plants as they consumed the leaves, then they moved on. Saltbush thrives on this cycle of intense foraging, then rest and recovery. Once ravaged the plants energy deposited in the roots is then called upon to restore new leaves and this is the key to saltbush’s survival. If continual defoliation occurs the root energy deposits become depleted and over time the saltbush plant finds it difficult to fully recover, ultimately it declines and then eventually the saltbush vanishes.

Today this gem of an Australian plant is recognised all over the world for its very useful qualities. It’s our very own home-grown superstar. It always seems that the grass is greener on the other side of the fence; we tend to import plants from overseas to try and solve our problems when often the best solutions are those under our own noses.

Regretfully not enough Australian agriculturists are quite as conscious of the Old Man Saltbush’s natural value. This initial lack of appreciation for saltbush is often short lived because most folks find a special place in their hearts for this brilliant plant. A spark of recognition ignites then this links thoughts immediately with Australia’s idealistic past. Old characters such as “Saltbush Bill” come into mind and the legend of Sir Sydney Kidman are remembered. The pioneers regard for Old Man Saltbush is safely preserved in Australia’s special way of life and our history forever.

Old Man Saltbush, Atriplex nummularia, is a member of the Chenopod family which are typically shrubs of all sizes. Commonly the leaves are covered with minute salty scales or soft silky hairs.

Wild Old Man Saltbush plant between Hay and Balranald New South Wales 2007

Old Man Saltbush can sometimes be referred to as Giant Saltbush or Cabbage Saltbush and is the largest of the Australian saltbushes. It is a large grey shrub which tends to develop woody branches. Up to 2m high and sometimes 4-5m across, the leaves are grey, roundish and fleshy.

Remnant Old Man Saltbush stand near Balranald New South Wales.

Saltbush grows predominantly on clay soils, usually in flat or low-lying situations but is also capable of growing on lighter soils providing soil pH is not strongly acidic. Trees such as Myall (Acacia pendula), Coolibah (Eucalyptus coolabah) and Black Box (Eucalyptus largiflorens) are commonly found growing amongst the very dense and solid stands of Old Man Saltbush

The deep robust root system which exploits a large volume of soil will withstand severe droughts. The tap-root has 3 main branching lateral layers, and more additional vertical roots from these laterals. Incredibly a secondary root feature of fine hair-like roots dwells just under the soil surface. Their purpose is to harvest moisture from the dewy mornings.

This huge root system also makes the plant a great recycler of nutrients by bringing deep deposits of nutrients into use and converting them into plant tissue. Over time the leaves drop these newly accessible nutrients to the soil surface or plant material is consumed by grazing animals.

Wild Old Man Saltbush between Hay and Balranald New South Wales

The grey colour of the plant serves another special purpose in that it does not absorb as much heat as a greener plant. The salt crystals also assist by reflecting sunlight away from the leaves. These adaptations are simple but serve the plant enormously to conserve water and keep it cooler during times of very high temperature.

Old Man Saltbush belongs to a very special, highly evolved collection of plants which use a process called C4 carbon fixation or C4 photosynthesis (the common type is C3). The plants that have this C4 pathway enjoy a distinct superiority in environmental conditions of drought, high temperatures and low nitrogen. Only 1% of known plant species possess this amazing ability.

Simply stated, the C4 refers to the process that produces a compound that occurs in the plant’s leaf tissue. Ultimately this compound has four carbon (C4) atoms present in its make up, rather than the standard three carbon atoms (C3) of most other plants. This unique conversion efficiency of the atmospheric carbon gas to plant material in a saltbush uses less oxygen, nutrients and water, with minimum destruction to the plant’s own living tissue during the process. This functioning efficiency is incredible!

Yet another unusual feature of Old Man Saltbush is that it is a halophyte; only about 2% of plants in the world possess this ability. Halophytes grow and utilise salt from the soil. Old Man Saltbush accumulates elevated salt concentrations in its roots and leaves. Often salt can be seen when the sun shines directly onto the leaf and a sparkle shines from the leaf surface. This same higher salt concentration in the plant’s roots at a cellular level draws additional water by osmosis to the plant from the soil. This process gives the plant a much increased drought resistance.

Old Man Saltbush has no obvious period of dormancy therefore it can be grazed at any time of the year. Growth does slow in winter like most other plants but this is mainly due to the shorter hours of sunshine and cooler temperatures. We are aware of Old Man Saltbush plants being at –8C, and they have been totally unaffected by these freezing conditions.

Meat produced from animals grazed on saltbush stands is sought after for its superior taste and tender quality. Fashionable restaurants and cafes list saltbush fed lamb or saltbush fed beef on the menu. Additional meat marketing opportunities, involving saltbush, lay in wait for innovative livestock producers with clear insight into consumer preference and requirements.

Wool production from Old Man Saltbush stands have qualities greater to wool grown in less controlled situations. The rotational grazing system and the saltbush, which is non-dormant, provides a more constant food supply to the stock during the year, therefore the wool continues to grow with good body and tends not to suffer from staple breakages due to inadequate nutrition. A well managed stand of old man saltbush also lessens the vegetable matter that often lodges in the wool fleece. This is due to the softness of the leaves and less burrs in the pasture.

The Old Man Saltbushes are large and leaves are held along branches. This causes most of the grazing to be off the soil level and well above the zone where worm eggs are present. The tendency to reduce the frequency of drenching is another feature of stock grazed on Old Man Saltbush stands.

There is evidence that the chenopodium oil found in many of the species of the Chenopodiaceae family may be present in Old Man Saltbush as well. Old Man Saltbush is a member of this family of plants. Chenopodium oil reduces internal parasites, and cuts down the impact to stock of external parasites.

Chenopodium ambrosioides (or American Wormseed) is a species related to Old Man Saltbush. This Central American plant contains substantial levels of chenopodium oil and has been used for centuries in Central and South America both in humans and livestock.

There is no readily available information available at the moment about the actual levels of chenopodium oil in Old Man Saltbush but if there is sufficient active ingredient in Old Man Saltbush, it may be one of the factors that contribute to the lesser parasitic problems experienced by livestock grazing the saltbush.

Old Man Saltbush plants and hedges often provide effective shelter from heat, cold and wind, especially useful for sheep “off shears” or for lambing ewes.

We at Inland Botanics have a vision that one day Australia’s interior may return to its former glistening grey-green glory with livestock herds again grazing contently through the saltbush forests.