Small - growing Eucalypts

....suitable for southern Victorian gardens *

Kevin Rule

Green Mallee-ashes

In my experience the green mallee-ashes, most of which occur naturally in alpine and sub-alpine areas of New South Wales, are the most reliable. Included in this group are Eucalyptus apiculata, E.approximans and its subspecies codonocarpa, E,burgessiana, E.cunninghamii (formerly E.rupicola), E.kybeanensis, E.obstans (formerly E.obtusiflora), E.paliformis, E. stricta, E.triflora, and an unnamed species from the Nowra area previously referred to as a green-leaved form of E.luehmanniana. Also include E.olsenii and the little sallees, E.moorei and its var.latiuscula, and you have a perfect group of species which will tolerate the harshest sites your garden can offer.

Eucalyptus cunninghamii (Cliff Mallee Ash). This species (formerly E.rupicola) grows on the rocky outcrops of the Blue Mountains around Katoomba where it is a shrub to 2m. In cultivation it does better than this and grows to 4m or so. Apart from its size and habit, it features blue, erect, linear leaves.

These species possess glossy-green adult leaves, as the name of the group suggests, although those of E.cunninghamii are somewhat bluish.

All species are smooth-barked and, with the exception of E.paliformis and E.triflora which are always small trees, are naturally relatively small mallees. Each species has its own particular feature, but the narrow leaves of E.apiculata, E.approximans, E.cunninghamii and E.moorei are extremely attractive; and the large broadly falcate leaves of E.burgessiana and the Nowra species are interesting curiosities. E.olsenii has its own unique quality in its large, barrel-shaped, prominently ribbed fruits which rival anything Western Australian.

Blue Ashes and Snow Gums

The blue ashes and snow gums, which include E.gregsoniana, E.luehmanniana, E.multicaulis, E.remota and E.stenostoma are also worth cultivating in the small suburban garden. Of these, E.luehmanniana, is highly ornamental with its large blue leaves and waxy buds and stems. Eucalyptus stenostoma is a relatively small, slender tree and is also waxy; and E.gregsoniana is a shrubby species which features smooth white bark and conspicuously glossy, often erect leaves.

Eucalyptus gregsoniana (Wolgan Snow Gum). Formerly, this species was known as E.pauciflora var.nana, but it has been separated as a distinct species on morphological grounds. Growing to about 3m, first as a small tree and eventually malleeing, it features weeping, falcate leaves, bright green buds, white stems and red branchlets.

Eucalyptus luehmanniana (Yellow-topped Mallee-ash). This species exists in both glaucous and non-glaucous forms, is endangered and is one of the most ornamental eucalypts in eastern Australia. It grows as a mallee, but cultivated specimens take on a tree form to about 4m. It has relatively large, creamy flowers and large, leathery pendulous leaves. The glaucous form is exceedingly attractive and rivals many ornamental species of Western Australia.

Mallee-box

South-eastern Australia also contains a number of mallee-box species which are good candidates for cultivation even though most occur in somewhat drier inland conditions. This group includes the much cultivated E.viridis, E.polybractea and E.lansdowneana (including its coastal form ssp.albopurpurea). Eucalyptus froggattii, E.odorata var.angustifolia and E.wimmerensis are other mallee-boxes which have received little attention from cultivators.

Eucalyptus polybractea (Blue Mallee). Growing from 4 to 10m, this is an attractive, hardy eucalypt from the mallee regions of New South Wales and Victoria. It has glaucous or subglaucous leaves and smooth stems, although some populations (tree forms) feature grey-black, rough bark for more than half the trunk. This species has been used extensively in the eucalypts oil industry.

Eucalyptus froggattii (Kamarooka Mallee). An endangered species, this eucalypt is confined to a few small populations in north western Victoria. Naturally, it is a mallee or tree to 12m, but in cultivation specimens have not reached that height. Its main feature is its relatively large, somewhat leathery leaves which are mid green and lustrous. Some growers may feel that it is potentially too tall for a suburban garden, but its endangered status makes it worthy of consideration.

Of these, typical E.lansdowneana with its profusion of crimson flowers, large green leathery leaves and dwarf habit is the most ornamental. Even though it is naturally a semi-arid species, its capacity to tolerate Melbourne's winters offers considerable rewards to the grower.

The bluish leaves of E.polybractea are particularly attractive, and even more so when suckering from the lignotuber. Just as attractive are the slightly narrow, glossy leaves of the bushy E.wimmerensis and the broader, glossy leaves of the larger E.froggattii.

Other Species

A number of other species natural to South-eastern Australia have the capacity to perform well in cultivation as small-growing specimens. These include E.anceps, E.barberi, E.behriana, E.calycogna and its var. staffordii, E.cneorifolia, E.curtisii, E.cyanophylla, E.flindersii, E.incrassata, E.leptophylla, E.pumila, E.saxatilis, E.sturgissiana and E.vernicosa.

Not one of these is unattractive in cultivation, but my favourites are E.saxatilis, which takes on the habit of a small, weeping tree and which has conspicuously waxy branchlets; E.sturgissiana, which has spindly stems covered in wax and which possesses persisting intermediate leaves; and E.vernicosa, the Varnished-leaf Gum, which features small, round, glossy-green leaves and which is truly a dwarf eucalypt.

Eucalyptus vernicosa (Varnished-leaf Gum). Growing on the mountain ridges of Western Tasmania, this eucalypt has the distinction of being the smallest known species, rarely reaching over 1m in height. It has small, lustrous leaves and a semi-prostrate habit, often spreading across the ground to a diameter of 5m. Specimens have been grown in damp, semi-shaded positions.

Whilst these species have been presented as being worthy of cultivation for a particular set of reasons, some are rare or endangered and should be tried for that reason alone. Ideally, they could be used to generate supplies of seeds so that their continuation is assured at least in cultivation.

* Editor's Note

1. Although written for conditions in Southern Victoria (cold, wet winters and hot, dry summers), many of the species mentioned will grow successfully in other areas.

2. A "mallee" is a eucalypt which grows as a number of relatively narrow stems arising from the ground rather than as a single-stemmed plant. Mallees are common in areas of the dry inland (where the term is often used to describe the characteristics of the overall vegetation) and they are also found in exposed, cliff-top areas.

Reprinted from the December 1990 issue of the Newsletter of the Victorian Region of SGAP.

Australian Plants online - December 1996
The Society for Growing Australian Plants