Recreating the Country blog
The lure of gold dust
Since it was first discovered in central Victoria in 185o, gold-dust has played significant part in the modern history of Australia. Thousands of hopefuls arrived on our shores prepared to live rough and make huge personal sacrifices in the hope of finding something yellow and precious. Even small quantities of gold dust would make fossickers jump for joy in paroxysms of pleasure. Though I started my working life as a geologist I could never fathom this obsession with gold.
In my early thirties I discovered native plants and realised that the gold dust that excited me wasn't found in stream sediments or deep underground. It's more easily found tantalizingly above the ground in quantities that would fill a gold fossickers bag in no time. It's extraordinarily beautiful and is valued by many more species than just Homo sapiens
Gold-dust Wattle, Acacia acinacea
Commonly pronounced -
Ass-in-ace-y - finishing with a pleasant upward inflection.
Its all Greek – acinacea/akinakes = short curved Persian sword or dagger
Its name refers to the clusters of remarkable and tightly curved small seed pods that form in early December.
Some human context
This beautiful small shrub produces large bunches of wattle flowers in Spring that are perhaps even more golden than Australia’s floral emblem, described in my previous blog. I’ve seen plants so heavy with flowers that they drooped to the ground under the weight. As an added attraction it has small rounded shiny leaves that give it a soft, delicate appearance throughout the year.
This delicate appearance belies its tough drought tolerant character making it suitable for most well drained soils. Like all wattles the Gold-dust Wattle adds nitrogen to the soil which benefits other native plants growing nearby.
An ideal plant for the home garden, though notably heavy pruning can make plants sucker, so a light pruning in small gardens may be preferred.
Its bushy nature makes it very suitable for mass planting as a low shrub layer in larger biodiversity plantings.
For more information on the Gold-dust Wattle click here
Restoring small remnants of Gold-dust Wattle
All wattles need large communities of at least 50 plants with diverse genetics to survive for the long term. In some locations the Gold-dust Wattle is in danger of dying out because of low numbers causing lack of plant diversity and inbreeding.
For example Gold-dust Wattle grows in the Bannockburn Bush and on the road-side between the towns of Bannockburn and Teesdale. These plant communities lack genetic diversity, are isolated (three kilometers apart) and small. The result of this is they produce very little fertile seed. The germinated seed also shows a lot of variation in vigor, a sure sign of inbreeding.
In 2010 the Golden Plains Shire funded the planting of 100 Gold Dust Wattles on the roadside next to the existing remnant community. These plants were grown from seed sourced outside the local area to boost the genetic diversity of this vulnerable plant community. This has lead to an increased production of viable and healthy seed.
The trusses of scented flowers are food for many insects. These flowers are a source of golden pollen and nectar for many native beetles, moths and butterflies.
These insects offer a diverse smorgasbord for insect eating birds. The seeds are food for native pigeons, parrots and quail. Ants also gather the seed for its oil rich aril that attaches the small black seed to the pod.
Insects also eat the seed frustrating seed collectors when they open the pods to find only brown dust inside.
Its bushy form makes it an ideal habit plant for small insect eating birds like the Superb Fairy Wren. Skinks, frogs and small mammals benefit from its low shelter particularly if some logs or rocks are added as part of the landscape design.
To read more about small insect eating birds try this excellent ‘Birds in Backyards’ link
Collecting seed - harvest time is usually late December to early January
The seed found in healthy plant communities is easy to collect because the pods are usually in clusters. With all wattles, waiting until the pods are opening with some seeds visible makes separating the seeds from the pods much easier.
I usually rub handfuls of pods between my gloved hands in a scrubbing motion to detach the seeds. A common garden sieve will aid cleaning by separating the seeds and the pods. Winnowing in a light breeze while pouring the seed from one bucket to another will remove the fine debris leaving the seed clean and ready for storage in a labelled zip-lock bag.
Remember to record the name of the species (a short description is good if you're not sure), where it was collected and the date of collection. Other information such as soil type and aspect is very useful when choosing the best home for your seedlings.
Pouring boiled water over the seeds then allowing them to cool is a convenient method. Seeds can then be sown into a seed raising mix or directly into the soil where they are to grow. Cover to a depth more or less equal to the thickness of the seed. They are a bit slower to germinate than other wattles, taking 2 - 4 weeks.
Germinated seed in trays can be planted in tubes as soon as they appear above the potting mix. This is a quick method that minimises the root damage that can occur when transplanting larger seedlings with more developed fragile roots.
For more information on propagating wattles go to this link and scroll to the end
- becoming wild in isolation
Golden Wattle, Acacia pycnantha.
Commonly pronounced - ‘Pick-nan-tha’
Some human context
One of our most internationally celebrated wattles is the extraordinary Golden Wattle, Acacia pycnantha. Every Olympic athlete wares the green and gold because of the golden flower clusters and the glossy green 'leaves' adorning this humble small tree.
Read why they are not true leaves but phyllodes in my May blog on acacias
… and it’s also our national floral emblem?
Its claim to super-celebrity status as Australia’s floral emblem is quite dubious in the light of its limited distribution. The Golden Wattle grows naturally in only three states; NSW, Victoria and SA and it’s a declared weed in Tasmania. Oops!
The story of making it to celebrity status can be summed up in three words - politics, charisma and money.
Translating its botanical name helps to appreciate its charismatic charms as pycnantha literally means ‘dense clusters of flowers’
More Greek – pyknos = dense & anthos = flower.
It may seem strange to read this now, but it was its commercial value in the early 1900's, as the richest source of natural tannin, that was the game changer. The powerful and influential leather industry in the more established eastern states threw their weight behind its choice.
This was enough to sway the members of the ‘National Conference of the Wattle Day League’ in 1913 to recommend the Golden Wattle as the national flower.
Though it took another 75 years of debate to have it declared Australia’s floral emblem in 1988.
Follow this link to read more about this fascinating history
The Golden wattle is a quick growing small tree that will reach its mature height of 5 meters in 3 - 5 years. It produces clusters of pollen rich flowers in winter & spring. This pollen is critical protein rich food for native bees and ants at the end of winter when there is a shortage of food. Beatles, butterflies and wasps find its sap-wood, leaves and seed irresistible as well.
In the web of life all these insects are a smorgasbord for the many insectivorous woodland birds.
It is relatively short lived (7-12 years), though it is very fast growing and quick to mature. This makes it the perfect pioneer small tree providing early shelter for the slower growing longer lived trees emerging around it.
The benefits of a short life
Having a short life results in quick establishment of fallen-log habitat in native bush and wider biodiversity plantings. This form of 'on-ground' shelter is critical for reptiles, amphibians, ground feeding birds and small mammals.
Its short life also offers other unexpected benefits to the ecology of forests and woodlands.
When it falls it disturbs the soil and opens up the overhead canopy letting in more sunlight and warmth. Sunlight, warmth and soil disturbance are necessary to kick-start new life in the form of the seeds of grasses, herbs, shrubs and trees lying dormant in the soil. The nitrogen it has added to the soil with the help of rhizobia will enable these new plants to establish more quickly.
Scroll to the end of my May blog on Acacias to read about amazing rhizobia
Caution to home gardeners
Its short lifespan and medium to large size makes it a poor choice for most home gardens and for narrow farm plantations. Its early demise will open gaps in narrow plantations and likely cause wind damage to adjacent trees and shrubs. In large gardens, wider farm plantations and native bushland its short life becomes a valuable asset to the ecology as mentioned above.
The Golden Wattle produces large quantities of edible seed from December to early January.
Efficient separation of the seed from the dry pods is made easier by choosing the right harvest time. The best time for seed collection is when the majority of the dry pods have started to open revealing the shiny black seeds inside.
Handfuls of pods can then be stripped from the tree onto a tarpaulin spread at the base of the tree. Many of the seeds will separate from the pods when they fall to the ground. A common garden sieve can be used to finish the seed cleaning, Store in zip-lock plastic bags until needed.
It is easy to propagate from seed using the boiling water treatment described at the end of the May 2020’s Acacia blog.
Next week I'll introduce a small local wattle with lots of charm though much less international fame.
Gold-dust Wattle, Acacia acinacea
Stephen Murphy is qualified in Geology and Environmental Management and has been a nurseryman and a designer of natural landscapes for over 30 years. He loves the bush, supports Landcare and is a volunteer helping to conserve local reserves.