2. Summary
There are some 1350 species of Acacia found throughout the world and close to 1000 of these are to
be found in Australia.
Commonly known as Wattle, Acacia is the largest genus of vascular plants in Australia.
Australia's national floral emblem is Acacia pycnantha, the Golden Wattle. Wattle Day is celebrated on
the1st of September each year.
They are particularly prevalent in the arid and semi-arid and the dry sub-tropical
regions of the country.
3. Flowering
Individual flowers are arranged in inflorescences that may be either globular heads or cylindrical
spikes. Each inflorescence may comprise from as few as 3 individual flowers (e.g. Acacia lunata) to as
many as 130 or more (e.g. Acacia anceps).
Acacia species flower throughout the year although the bulk of species flower during spring and
summer and a lesser number flower during autumn and winter.
Flowers can vary in colour through cream, pale yellow to gold. One species, Acacia purpureapetala,
has purple flowers whilst a form of Acacia leprosa has red flowers. The flowers of many species are
delicately perfumed.
4. Gardening Tips
The words everyone associates with planting a wattle are “fast-growing but
short-lived”.
Wattles are quick because many are pioneer plants. They spring up in
disturbed areas or after fire, their nitrogen-fixing roots helping the soil, and their flowers and leafy branches
offering food and shelter for animals, insects and birds.
Then after a few years other trees and shrubs have arrived and those first, eager-to-please
wattles start to wind down, often attacked by borer.
The fast-growing but short-lived species shouldn’t be dismissed as being no good. They are
a great plant to use to establish a garden, and make fast windbreak and privacy plants.
And plants are cheap.
Planted at tubestock size, and given care during their first spring and summer, they soon
begin to grow. Provide water and give protection from browsing animals to see a tube-sized
plant reach an impressive metre or more in a year.
5. Pests
The main pests are stem borers which can be controlled by probing with flexible wire or by injecting a
few millilitres of alcohol into the holes.
Galls are often more difficult to control, but removing the effected branches can reduce the problem.
Acacia Bug (Eucerocoris tumidiceps) can cause damage to the foliage of wattles with phyllodes and is
difficult to control. Treatment with a systemic insecticide may be required.
6. Bush Tucker
Several species of Acacias are more palatable and commercially viable, these being;
• Ac victoriae – Prickly Acacia
• Ac. sophorae – Coastal Wattle
• Ac retinodes – Wirilda
• Ac coriacea – Dogwood
• Ac murrayana – Colony Wattle
• Ac aneura – Mulga.
In their natural habitats these species are plentiful, and because of this, they have been
mainly harvested in the wild. The most sought after wattleseed is the Ac retinodes – Wirilda,
which is now being planted in large commercial plots for the bushfood industry.
The seeds of the Acacias have very hard husks, and when they fall to the ground, will last for
up to 20 years in their natural environment, usually only germinating after bushfires. Because
this hard outer casing also protects the seed during long periods of dormancy on the ground,
Wattleseed has provided indigenous Australians with a rich source of protein and carbohydrate
in times of drought. The seed was crushed into flour between flat grinding stones and cooked
into cakes or damper. Even the green seeds of some species were eaten after baking in the
hot coals.
7. Bush Tucker cont.
Save wattleseed grounds after making Wattleseed Tea to add to biscuits & cakes.
Roasted ground Wattleseed has a diverse number of uses in the kitchen, from baking to thickening
of sauces and casseroles, to ice cream. By dark-roasting Wattleseed, the most delightful aroma of
nutty fresh roasted coffee is released and can be used as a beverage or as an addition to chocolate
or desserts.
The Aboriginals used wattle seed to make a type of flour. They cooked this often in ovens made in a
hole in the ground using hot coals and hot rocks. Wattle seeds are very nutritious. Some types were
also eaten green or cooked in the pod.
Wattleseed Recipes
http://tasteaustralia.biz/bushfood/wattleseed/wattleseed-recipes/
8. Propogation
Acacias are generally grown from seed. Some of the smaller species may be propagated from cuttings. Seeds, because of their hard seed coat, require
treatment before sowing. This usually entails either pouring near-boiling water over the seeds, or scarifying the seed coat (such as by rubbing between
two pieces of glasspaper, or nicking the end opposite the aril), and then soaking in water. In one report it was found that nicking the seed coat resulted in
a 100% germination rate after one week as against a lower germination rate after 3-4 weeks using a 30 second boiling water pre-treatment.
Following such treatment some of the seeds will have swollen. Those that have not are not necessarily infertile. The seeds of a wattle plant, like the seeds
of many other sclerophyllous plants, vary in the length of time they require to germinate in response to suitable germination conditions. This is an
evolved safeguard against natural disaster. The seeds may be sown into a normal sowing mix, such as a 1:1:2 mix of washed sand:peatmoss
substitute:sandy loam. Germination may occur within several days and continue for some weeks. Spring and early summer appear to be the best times
for sowing. Autumn and winter sowings tend to be slow to germinate and produce less vigorous seedlings, or fail to germinate. Successful germination
may be had using immature (green) seed and sown without pre-treatment. This may be advantageous when the soaking of mature seed encourages
fungal growth. The use of dry heat and microwaving of mature seed can also be used to alleviate these problems, but care is required especially when
using microwave treatments.
Following germination, the seedlings should be potted up without excessive root disturbance. As most species occur in infertile soils, fertilising should be
done cautiously. Generally a low phosphorus, slow release fertiliser is preferred when considered necessary. Many of the species from arid areas
produce, quite quickly, extensive root systems, and for such species planting out should not be delayed.
Propagation from cuttings may not give satisfactory results. Half-ripened wood, taken in spring to early summer is generally regarded as the most
dependable .
Most wattles prefer a sunny position in a light, well drained soil. However, many are quite adaptable in their light and soil requirements. Many are also
drought tolerant and are hence useful in dry areas. Frost tolerance is variable. As a general rule, species from the coastal forests and woodlands are less
tolerant of dry semi-arid conditions, and conversely, those from the dry interior do not generally tolerate high humidity.
9. Types of Wattle
Acacia macradenia (Zig-zag Wattle)
Native to Queensland.
Shrub up to 3-5 m high with zig-zag stems.
Phyllodes narrow-lanceolate, 15-25 cm long and 2-3 cm wide.
Flowers in globular heads, golden yellow, appearing Jul-Aug.
Not expected to tolerate frosts. Suitable for subtropical regions.
10. Acacia dunnii (Elephant Ear Wattle)
Native to Western Australia and Northern Territory.
Open shrub or small tree up to 6 m high, rarely higher.
Phyllodes are the largest of all Acacias and are up to 45 cm long and
30 wide, hence the common name. Flowers in globular heads.
Not expected to withstand frosts. Suitable for planting in tropical and
subtropical regions and noted for its novelty value.
11. Acacia conspersa
Native to Northern Territory.
Tree up to 7.5 m high but often a shrub. Phyllodes
narrow-lanceolate, 4-10 cm crowded.
Flowers in spikes up to 5 cm long, bright golden-yellow,
appearing Apr-Jul.
Not expected to be frost hardy.
Suitable for planting in tropical and subtropical regions.
12. Acacia holosericea (Silky Wattle)
Native to Western Australia, Northern Territory and Queensland.
Erect or spreading tree up to 8 m high. Phyllodes mostly lanceolate,
7-10 cm long and 1-3 cm wide, greyish-green.
Flowers in spikes 3-8 cm long, golden yellow, appearing Jun-Aug.
Not expected to be frost hardy. A widely cultivated species in northern
Australia and suitable for tropical and subtropical regions.
Useful for shelter and soil erosion control.
13. Acacia pycnantha (Golden Wattle)
Native to South Australia, New South Wales, Australian Capital Territory and
Victoria, and has been introduced to the Perth District, Western Australia.
Small spreading tree to 3-8 m under good conditions. Phyllodes variable in
shape ranging from obovate and oblanceolate to narrow lanceolate and
sometimes falcate, 6-20 cm long and 1-5 cm wide, occasionally wider.
Flowers in large globular heads, bright golden-yellow, appearing Jul-Oct.
Moderately frost hardy. As Australia's National Floral Emblem, this wattle is always
worthy of planting and does well in temperate regions where severe frosts
are absent. A local "strain" of the Golden Wattle in the Canberra region will
survive very cold winters but the usual form from South Australia and Victoria
might not unless it is well protected.
14. Acacia purpureapetala
Sprawling, prostrate shrub to 0.5 m high;
new growth purplish.
Pods narrowly oblong to elliptic, to 30 mm
long, 4–7 mm wide.
A rare species confined to the Herberton
region, Qld. Grows on steep rocky slopes in
Eucalyptus woodland; often colonises disused
mine sites. Flowers sporadically, though
not prolifically, throughout most of the year
but main flush in June- July.
Unique among the Australian acacias
in having consistently mauve-pink flowers.
15. Acacia leprosa (Cinnamon Wattle - red flowered
form) Scarlet Blaze
Newly Discovered Wattle Becomes Victoria's Federation
Floral Emblem
Scarlet Blaze, one of the twentieth century's most
surprising and significant horticultural discoveries is
Victoria's
Centenary of Federation floral emblem.
The blood-red variety of the Cinnamon Wattle was found
growing in a Victorian forest in 1995 by two bush walkers.
They took cuttings to the Royal Botanic Gardens,
Melbourne, which manages a specialised plant
conservation program, thereby saving many plants from
probable extinction.
16. Acacia courtii (Northern Brother Wattle)
A rare wattle native to the mid north coast of Australia.
It is a tall shrub or weeping tree growing to 7-20m in height. The bark is
smooth and grey when young and later becomes black and furrowed. Small
branches are a maroon brown colour. The leaves are dull green and narrow,
up to 18 cm long, and have a small gland on the leaf edge just above the
stem.
From late spring to mid-summer spikes of pale yellow globular flowers are
produced followed by straight or curved, narrow woody pods up to 18 cm
long.
This wattle usually grows on steep, dry, rocky slopes and in mixed dry forest
on shallow soils, often under a canopy of White Mahogany and Grey Gum.
