Saturday, July 25, 2015


Acacia harpophylla

You have to be lucky, to catch brigalow in flower. The plants will often go for years without it. However this season seems to be a good one, so look out for the flowers.

This undervalued plant is one of Australia’s prettiest wattles, but not so much for its rare flowers as for its beautiful, sickle-shapes leaves, its black trunk and branches, and its graceful form.


In certain lights, the leaves are a lovely shade of silver. They are especially good in the sunshine after rain, while they are still wet.

In other lights, the trees have a dull grey, almost sinister beauty.

Brigalows sucker if damaged or cut down. This can be a nuisance to those who want to clear paddocks for agriculture, but is an advantage to those who want fresh, young, edible regrowth within reach of their cattle.
It also means that a row of brigalow can be turned into an effective windbreak with a bit of deliberate damage around the lower trunks to promote suckering.
For those who complain that wattles are short-lived, here's one that can live to a great old age.

Brigalow is the main inland host plant for the critically endangered butterfly, the pale imperial hairstreak Jalmenus eubulus. Unfortunately, it breeds only in old-growth forest or woodland and does not appear to colonise regrowth habitats following clearing or other major disturbance. This is a very good reason for conserving areas of old-growth brigalow.
Sadly, another threat to this and others of our more beautiful endangered butterflies are those so-called “nature lovers” who express their love by owning and displaying dead butterflies.  It is illegal to "collect" (as in "kill") butterflies in Australia without a permit, but this does not deter the unscrupulous.

Propagating brigalow is easy, provided you know the tricks, and its tricks are different from those of most wattles.
Seed of most Acacia species is very long-lived. It can be stored for at least 25 years and probably much longer. When the time comes for planting, you put a few seeds in a coffee cup, pour boiling water over them and leave them overnight. The seeds swell (repeat the treatment for the ones that don’t) and can be planted, germinating in a week or two.
Brigalow is different, though. It’s thin-skinned seeds are short-lived, so there’s no point in storing them as they’ll only die in storage. They need to be planted as fresh as possible, and without subjecting them to boiling water, which would kill them. Treated this way, they germinate within days.
Given that flowering and seed production are erratic, producing new little brigalow plants is a matter of taking advantage of opportunities when they occur, and this coming season looks like providing that.

Friday, July 24, 2015

Common Wilga

Geijera parviflora

This type of scenery was once very common on the Darling Downs. A high, open canopy of Eucalyptus species was partially filled below with a lower canopy of common wilga and other dry vine scrub species.

The Lake Broadwater Regional Park* near Dalby preserves a portion of it. It is rich in wildlife because of the mosaic of varied environmental niches that this type of habitat provides. There are windbreaks and nectar for butterflies; grassy patches and shade for the kangaroos, nutritious fruits for birds, sheltering undergrowth for lizards and tiny mammals, and so on.
It’s a great spot for orchard butterflies, which breed on the wilga leaves, and for nesting birds, which come for the protein-rich mixture of edible insects attracted by the long winter/spring flowering season of the wilgas.

We are more familiar with wilgas as fence-line survivors in our farmscapes, where there are easily identified by their shape. They look like great green beach balls.

Where sheep graze under them, the lower half of the foliage disappears, leaving shady green umbrellas.

They make pretty garden plants, as seen in this young one photographed (above) in Peacehaven Botanic Garden in 2012.
They are also fast-growing. It was twice the height when I photographed it recently (below).

Wilga’s wild-life supporting credentials mean that it is more than a stand-alone addition to a garden. Like so many “scrub” plants, we can leave it show off its beautiful ground-sweeping shape, or we can imitate sheep and trim it up from below for a pretty little shade tree.
The strongly vertical lines of the dense narrow foliage make it a good background or contrast plant.

 Wilgas belong to the Rutaceae family. Like the other members (including citrus fruits), the crushed leaves release a very pleasant fragrance.


Wilgas are notoriously difficult to grow from seed.
Sarah Caldwell, who was a recent guest speaker at a Toowoomba Society for Growing Australian Plants meeting, said that the secret is to peel off the little black seed coats to remove the chemical that inhibits germination. I can’t wait to try it!
Other techniques used are to put seed-rich soil from under older plants into seed trays and water it. Older seeds which have lost their inhibitions will grow.
Or you can put fresh seeds in a muslin bag and hang it in a toilet cistern for a few months. The frequent changes of water are said to flush out the inhibiting chemicals.

This plant is very hardy to both frosts and droughts.

* For those who like to ponder on matters political, it is interesting that the Broadwater park has had a recent name change. Its status as a “Regional Park” is new. Until the Newman government was elected and decided to fiddle with nomenclature and other aspects of our environment protection laws, it was called the “Lake Broadwater Conservation Park”. Gazetted in 1881 to conserve the only large, naturally-occurring freshwater lake on the Darling Downs and its flora and fauna, it is a nationally important wetland.

It was an odd thing to do, to carefully remove the word “conservation” from the names of our state’s Conservation Parks. What were they thinking?
And why has the current Labor Government, which was so fiercely opposed to the raft of changes made by the Newman Government to Queensland’s Nature Conservation Act, not changed it back?
The ways of politicians are mysterious indeed.

Small leafed Condoo

Planchonella cotinifolia
(Pouteria cotinifolia)



It is a bit hard to find specimens of this plant out in the open, as its preferred habitat is in the local rainforest type known as “dry vine scrub” or “semi-evergreen vine thicket”.
This one, however, has been left when scrub was cleared for grazing. It could be as much as two hundred years old, but a long period in the open has given it plenty of time to fill in its canopy to its pretty, natural shape.

Cattle love the leaves, (as is usually the case with dry vine scrub species). They have eaten all of this plant they can reach, revealing its trunk.
Cattle-pruning tells us how well a tree would respond to treatment with the secateurs, and you can see that this is a flexible plant which could have a number of garden uses.
As a naturally small tree, it would be very suitable for a suburban garden or as a street tree, never likely to outgrow a well-chosen site. Grown among other trees or shrubs, it forms the trunk like that in the photo, though often single. Its canopy shapes itself to share the space with whatever else is growing close.
The regrowth at the base of the tree in the photo tells us that it would grow a leafy canopy to ground level if left by itself to grow in an open position. It could be a useful tall screening plant.
If a tree shape is wanted in an exposed open site, it would be a simple matter to trim off the lower branches.
Another cattle-pruned specimen seen (sorry, I didn’t photograph it) must have been exposed to cattle when much younger. All-over pruning has resulted in a dense-foliaged waist-high shrub, demonstrating the potential of small-leafed condoo as a hedging plant.

Like many other members of the Sapotaceae family, condoos have milky sap and edible fruit. (Black sapote, for example, is popular in tropical and sub-tropical Australia, where it is often grown by lovers of unusual fruits)
Small-leafed condoo’s fruit is small, but delicious.

Well-sucked seeds like this one can be planted to make new trees.

This was once a common plant on the red soil around Toowoomba. Many are now being cleared as real estate development radiates from the Highfields area, though occasionally the developers leave a pretty specimen as they clear. Replanting the same species in the resulting new gardens would be a positive step for our local environment.
Although not recorded as a butterfly host plant, it may well support blue triangle butterflies, as do some closely related condoo species. If you have one, take note of the caterpillars that use it. You could well add something new to add to Australia's still rather sketchy knowledge of its own wildlife.

Bear's Ear

Cymbonotus lawsonianus

Here’s a little native daisy that we most often see in winter and spring after good rain, so look for it now.
Its normal habitat is open grassy woodland, and it likes the space around it to be rather open, so it can spread its leaves out flat.
I photographed the above specimen in Allora Mountain Reserve, which must have been opened for use by cattle at the time, as it was showing signs of heavy grazing. This is one of the few native grassland species that thrives on the treatment.
Bears ear is a hardy, stemless plant, with a rosette of white-backed leaves that sit flat on the ground and look a little like dandelions. The flowers are 3cm yellow daisies, which cluster tightly in the centre, close to the ground. The whole plant usually only rises a few centimetres high, though it can get up past your ankles if it is competing with grass or other low garden plants. It dies out if the grass gets too tall for too long, though.
This little daisy is suitable for flower gardens and shrubberies, and it copes well with mowing, which makes it suitable for establishing in a native grass lawn. It may also invade a lawn of the traditional kind, especially if it is well-watered.
Bear’s ear can be grown from seed, which will be ripe in the next few months. It's not commercially available, so you may need to collect your own if you want to grow it.
It needs good soil moisture to get established and to look its best. However it will survive (once established) with no watering at all. In dry times it dies back to its (edible) underground tubers, only reappearing in response to rain or watering.