Saturday, June 21, 2008

Mountain Coolibah

Eucalyptus orgadophila
This is a handsome tree of the fertile basalt hillside soils to the west of the dividing range, and is common in the outskirts of Toowoomba. It prefers a neutral pH, and a good proportion of phosphorus. Where it occurs naturally it is an indicator that these conditions occur. There are some Australian plants which really don’t like phosphorus at all – so the natural occurrence of Mountain Coolibah may tell you that Banksias and Grevilleas, for example, just won’t do well in your garden.
Mountain coolibahs are “half-barks, whose grey fibrous bark persists on the lower trunk. The beautiful smooth pale grey branches shed their bark every spring.
They are outstanding trees for wildlife. Koalas love the leaves. Old trees make good hollows (see article below), which are safe havens for gliders and other shy bush creatures. And it's a good honey tree, flowering in late winter.
Our most drought-hardy orchid, the beautiful black orchid of the west (Cymbidium canaliculatum) survives drought by sending its great mass of roots deep into its cool hollows - sometimes as far as 10 metres!
These are middle-sized eucalypts, still too large for our closer suburbs, but very suitable for small acreage gardens, and are drought and frost hardy.
In our original mountain coolibah woodlands, kangaroo grass Themeda triandra, which is now so fashionable for landscape gardening in the cities, was the dominant grass. Overgrazing has caused it to be supplanted by other grasses on our farms, but planting kangaroo grass with this tree in a garden setting would be a nice touch. Its bird attracting seeds would add to the wildlife appeal of your coolibah corner.

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