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.

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