Wednesday Weed – Mimosa/Silver Wattle

Mimosa/Silver Wattle (Acacia dealbata)

Dear Readers, you would think that I would pay more attention to something as bright and yellow as this small tree, especially as there is one in full flower next door as I speak. But, for some reason, the sheer magnificence of this Australian plant has past me by until this Saturday, when I stood in a hailstorm trying to take a few pictures. It really is an eye-blasting explosion of sunlight on a freezing cold March day, so I decided to try to find out some more about it.

Firstly, Mimosa is a member of the bean family (Fabaceae). All of the plants in the genus Acacia are found in Australasia, and all of them are fire-adapted, something that probably dates back at least 20 million years. The plant has deep roots, its seeds may germinate more quickly after being exposed to fire, and mature stands of trees can regenerate after a fire has passed through. However, the plant’s Achilles heel, at least in the UK, is its lack of frost tolerance – an extended period below -5 C is enough to kill young plants. I can only think that the two that I know of in East Finchley are protected by the urban heat island effect, whereby the warmth radiating from the buildings stops the temperature from dropping too far for too long.

Mimosa, in its native habitat, is a coloniser species, much as birch is in the UK. It cannot withstand being shaded out by bigger trees, and it has a short life span of only 30 to 40 years, which might explain why it isn’t as popular as it might be as a street tree, in spite of all the ‘Acacia Avenues’ of suburbia.

The flowers of the mimosa are given to women on International Women’s Day in Italy, Russia, Georgia and Armenia, and I remember seeing lots of small boys dressed as Batman and Superman, lots of little girls dressed as princesses, and lots of mothers carrying bunches of mimosa flowers. The smell of the plant is difficult to describe, but it has a sweet floral quality that is rather appealing. Not that I could smell it on Saturday, what with little ice pellets bouncing off my head, but I can still remember it.

The feathery foliage is very appealing too.

Photo One by By Stephencdickson - Own work, CC BY-SA 4.0,

New growth on Mimosa (Photo One)

The plant’s alternative common name, Silver Wattle, might refer to a white lichen which colonises the plant in Australia, or possibly to the silvery tint of the foliage of the canopy in a mature tree. ‘Wattle’ comes from an old word for ‘weave’, and the fibre of the tree has been used by the indigeonous Ngunnawal people of Australia to make rope for millenia. The Ngunnawal also use the sap as glue, the timber for tools and the seeds to make flour.

Photo Two from

Nineteenth Century Timber Sample from Victoria Museum, Australia (Photo Two)

Sadly, not everyone loves the Mimosa – it is considered an invasive alien in South Africa and New Zealand, and also gives cause for concern in Spain. I’m sure that its pioneering nature can cause a veritable thicket of mimosa to emerge at the drop of a hat.

The whole Wattle/Acacia family can be considered as a symbol of Australia – the plant features on the country’s coat of arms, along with the kangaroo and the emu. The green and gold colours of the Australian cricket team are said to be inspired by the plant, and when the surviving soldiers left the Gallipoli peninsula, their chaplain is said to have planted wattle seeds so that something of Australia would be left behind. During the First World War, mothers would send sprigs of wattle in their letters to their sons, and this inspired a poem by A.H Scott of the 4th Battery of the A.F.A. I suspect that there is no homesickness like that of a young man facing his death on the other side of the world.

A Little Sprig of Wattle

My mother’s letter came today,
And now my thoughts are far away
For inbetween its pages lay
A little sprig of wattle.

“The old house now looks at its best,”
The message ran: “the country’s dressed
In spring’s gay cloak, and I have pressed
A little sprig of wattle”.

I almost see that glimpse of spring
The very air her seems to ring
With joyful notes of birds that sing
Among the sprigs of wattle.

The old house snug amidst the pines,
The trickling creek that twists and twines
Round tall gum roots and undermines,
Is all ablaze with wattle.

Australian Coat of Arms (Public Domain)

Photo Credits

Photo One by By Stephencdickson – Own work, CC BY-SA 4.0,

Photo Two from

8 thoughts on “Wednesday Weed – Mimosa/Silver Wattle

  1. Fran & Bobby Freelove

    A coincidence you’ve done Acacia as your blog. I admire the large one that is outside the window of the chemotherapy suite where i’m having my treatment at Mount Vernon. It is an absolute picture especially when the sun’s shining, also to have something in full flower at this time of year is lovely. As you say it’s a tender plant until it’s well established

    1. Bug Woman Post author

      It’s nice to see something so pretty when you’re in a hospital I always think. Dorset County Hospital used to have herring gulls breeding on the roof, so you could watch the fluffy babies running around. Dad was always much more excited by the Air Ambulance though….thinking of you xxxx

  2. Anne

    In South Africa we harbour mixed feelings about wattle. Black Wattle was initially introduced (along with Eucalyptus and pine) for timber during the 1800s. As the bark contains high levels of tannin, which can be used to cure and colour leather, more trees were planted to produce the tanning extract for the leather industry. Working for Water teams have managed to rid large areas of wattle over the years (thus improving natural water sources) but the trees have escaped and are marching all over the country. As pretty as the flowers are, we cannot help viewing all wattle as a pest!

    1. Bug Woman Post author

      Like any plant that’s moved without its pests and predators coming along too, it can turn into a monster, sadly. Humans are so short-term when it comes to moving plants and animals about….


Leave a Reply