Vic Native Bonsai

Our feature tree this month is the group of trees which often come under the common name of Sheoak, and which includes quite a number of species grouped in two genera, Casuarina and Allocasuarina. Where previously Sheoaks were mostly all described as Casuarina, these were separated into separate genera in around 1980.

Allocasuarina includes around 60 species, all of which are endemic to Australia, while the closely-related Casuarina genus includes about 17 species, which are distributed across Australia, the Indian subcontinent, south-east Asia, islands of the western Pacific, and eastern Africa.

While quite a few different species of Allocasuarina and Casuarina have been used as bonsai, three species of particular interest to VNBC members are Allocasuarina littoralis, or Black Sheoak, Allocasuarina torulosa, or Rose Sheoak, and Casuarina cunninghamiana, or River Sheoak.

Black Sheoak occurs as a medium-sized tree along the eastern coastal areas of Queensland, NSW, ACT, Victoria, and Tasmania, usually growing in woodland and sometimes in tall heath, and often growing in sandy and other poor soils. Rose Sheoak is a medium-sized tree, native to the surrounds of rainforest areas in eastern and coastal Queensland and NSW. River Sheoak naturally occurs as a tallish tree in sunny stream banks and swampy areas from Northern Territory through to Queensland and southern New South Wales.

The characteristic fine needle-like foliage and the rough, ridged bark of sheoaks makes them an interesting subject for training as bonsai in a variety of styles.

These trees featured below are just a small selection of VNBC members’ trees displayed in recent exhibitions by the club.

Melaleuca styphelioides, or Prickly Paperbark, is a ready favourite species for many bonsai growers, with its characteristic fast growth rate, its ability to respond readily to pruning, wiring and trimming, and its classic papery bark developing in quite young plants.

This species, one of many in the Melaleuca genus, has a natural distribution mostly in the moister coastal areas of New South Wales and into Queensland. It is found mostly along waterways, as well as in some tableland areas. Prickly Paperbark has been used extensively as an ornamental street tree in Sydney and Melbourne, and has been widely planted in parks, gardens and in farm shelterbelts, due to its ability to thrive in a variety of environmental conditions.

The classic form of Prickly Paperbark in the open is an upright tree of up to 20m height, with a dense crown of small, tight, pointed leaves, with spikes of small, creamy white flowers in the bottlebrush form. The papery bark readily peels off the trunk in large strips.

When grown as a bonsai, this species responds readily to repotting, root pruning, wiring and branch pruning, allowing for development of a wide variety of styles.

This is, of course, just one of the great diversity of Melaleuca species native to many parts of Australia. Others of this genus vary widely in their growth habits, leaf shapes, bark characteristics, and most of these other species are also readily grown as Bonsai. More will be featured at later dates.

Every month, we aim to feature one Australian native species as bonsai, with reference as to how that species grows in the wild.

This month, May 2020, our feature tree is Leptospermum laevigatum, commonly known as Coastal Tea Tree, which has been a favourite species of many of our club members, and which has proved itself as a species which can be used in a wide variety of styles. With a small, oval leaf form, interesting flaky bark, and ready response to training and wiring of younger branches, this tree has been grown as spectacular windswept bonsai, as well as informal upright trees, and plenty of other styles reflecting the natural growth habits and adapability of the tree.

This species has a natural distribution across coastal areas of south eastern Australia, primarily in Victoria, Tasmania and New South Wales, and particularly on sandy dunes. It has, however, also been grown extensively in South Australia, Western Australia and south east Queensland, and has been introduced to a number of overseas countries, including locations in South Africa, New Zealand, California and Hawaii.

Coastal Tea Tree grows in a fascinating variety of forms, and the influences of its coastal exposure often results in trees with strange, twisted shapes naturally. The trunks of mature trees are characterized by their rough, ropy and twisted appearance, with thin, flaky bark.

The two photos above show some of the forms exhibited by trees in coastal Victoria, while below are a couple of examples of Leptospermum laevigatum as Bonsai.

In addition to this species of Leptospermum, there are about 83 species of Tea-tree across Australia, with 17 species in Victoria. Many of these species, including some of the available cultivars, are highly regarded as bonsai material.